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HYDRA-MATIC

4L30-E
CONTENTS
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
HOW TO USE THIS BOOK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
UNDERSTANDING THE GRAPHICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
TRANSMISSION CUTAWAY VIEW (FOLDOUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
PRINCIPLES OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9A
MAJOR MECHANICAL COMPONENTS (FOLDOUT) . . . . . . . . . . . . . . . . . . . 10
RANGE REFERENCE CHART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
TORQUE CONVERTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
APPLY COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
PLANETARY GEAR SETS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
HYDRAULIC CONTROL COMPONENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
ELECTRONIC CONTROL COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
POWER FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
COMPLETE HYDRAULIC CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
LUBRICATION POINTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
BUSHING, BEARING & WASHER LOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
SEAL LOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
ILLUSTRATED PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
BASIC SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
PRODUCT DESIGNATION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

2

PREFACE
The Hydra-matic 4L30-E Technician’s Guide is primarily intended for
automotive technicians that have some familiarization with an automatic
transaxle or transmission. Other persons using this book may find this
publication somewhat technically complex if additional instruction is not
provided. Since the intent of this book is to explain the fundamental mechanical, hydraulic and electrical operating principles, some of the terminology used is specific to the transmission industry. Therefore, words
commonly associated with a specific transaxle or transmission function
have been defined as needed throughout this publication.
The Hydra-matic 4L30-E Technician’s Guide is intended to assist technicians during the service, diagnosis and repair of this transmission. However, this book is not intended to be a substitute for other service publications
that are normally used on the job. Since there is a wide range of repair
procedures and technical specifications specific to certain vehicles and
transmission models, the proper service publication must be referred to
when servicing the Hydra-matic 4L30-E transmission.

© COPYRIGHT 1992 POWERTRAIN DIVISION
General Motors Corporation
ALL RIGHTS RESERVED

All information contained in this book is based on the latest data available
at the time of publication approval. The right is reserved to make product or
publication changes, at any time, without notice.
No part of any Powertrain publication may be reproduced, stored in
any retrieval system or transmitted in any form or by any means,
including but not limited to electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of Powertrain
Division of General Motors Corp. This includes all text, illustrations,
tables and charts.

1

INTRODUCTION
The Hydra-matic 4L30-E Technician’s Guide is another Hydra-matic publication from the Technician’s
Guide series. These publications provide in-depth
technical information that is useful when learning or
teaching the fundamental operations of a transaxle or
transmission. This book is designed to graphically
illustrate and explain the function of the mechanical,
hydraulic, and electrical systems that make up the
Hydra-matic 4L30-E transmission. The information
contained in this book was developed to be useful for
both the inexperienced and experienced technician.
The inexperienced technician will find the explanations of the basic operating characteristics of this
transmission as valuable when learning the function
of each component used in this transmission. The
experienced technician will find that this book is a
valuable reference source when diagnosing a problem with the vehicle.
In the first section of this book entitled “Principles of
Operation”, exacting explanations of the major components and their functions are presented. In every
situation possible, text describes component operation during the apply and release cycle as well as
situations where it has no effect at all. The descriptive text is then supported by numerous graphic illustrations which further emphasize the operational theories presented.
The second major section entitled “Power Flow”,
blends the information presented in the “Principles
of Operation” section into the complete transmission
assembly. The transfer of torque from the engine

through the transmission is graphically displayed on
a full page while a narrative description is provided
on a facing half page. The opposite side of the half
page contains the narrative description of the hydraulic fluid as it applies components or shifts valves in
the system. Facing this partial page is a hydraulic
schematic that shows the position of valves,
checkballs, etc., as they function in a specific gear
range.
The third major section of this book displays the
“Complete Hydraulic Circuit” for specific gear ranges.
Foldout pages containing fluid flow schematics and
two dimensional illustrations of major components
graphically display hydraulic circuits. This information is extremely useful when tracing fluid circuits
for learning or diagnosis purposes.
The “Appendix” section of this book provides additional transmission information regarding lubrication
circuits, seal locations, illustrated parts lists and more.
Although this information is available in current
model year Service Manuals, its inclusion provides
for a quick reference guide that is useful to the technician.
Production of the Hydra-matic 4L30-E Technician’s
Guide was made possible through the combined efforts of many staff areas within the General Motors
Powertrain Division. As a result, the Hydra-matic
4L30-E Technician’s Guide was written to provide
the user with the most current, concise and usable
information available with regards to this product.

3

HOW TO USE THIS BOOK
First time users of this book may find the page layout
a little unusual or perhaps confusing. However, with
a minimal amount of exposure to this format its
usefulness becomes more obvious. If you are
unfamiliar with this publication, the following
guidelines are helpful in understanding the functional
intent for the various page layouts:
•

Read the following section, “Understanding the
Graphics” to know how the graphic illustrations
are used, particularly as they relate to the
mechanical power flow and hydraulic controls
(see Understanding the Graphics page 6).

•

Unfold the cutaway illustration of the Hydra-matic
4L30-E (page 8) and refer to it as you progress
through each major section. This cutaway provides
a quick reference of component location inside
the transmission assembly and their relationship
to other components.

•

•

4

The Principles of Operation section (beginning on
page 9A) presents information regarding the major
apply components and hydraulic control
components used in this transmission. This section
describes “how” specific components work and
interfaces with the sections that follow.
The Power Flow section (beginning on page 41)
presents the mechanical and hydraulic functions
corresponding to specific gear ranges. This section
builds on the information presented in the

Principles of Operation section by showing
specific fluid circuits that enable the mechanical
components to operate. The mechanical power
flow is graphically displayed on a full size page
and followed by a half page of descriptive text.
The opposite side of the half page contains the
narrative description of the hydraulic fluid as it
applies components or moves valves in the system.
Facing this partial page is a hydraulic schematic
which shows the position of valves, checkballs,
etc., as they function in a specific gear range.
Also, located at the bottom of each half page is a
reference to the Complete Hydraulic Circuit
section that follows.
•

The Complete Hydraulic Circuits section
(beginning on page 67) details the entire hydraulic
system. This is accomplished by using a foldout
circuit schematic with a facing page two
dimensional foldout drawing of each component.
The circuit schematics and component drawings
display only the fluid passages for that specific
operating range.

•

Finally, the Appendix section contains a schematic
of the lubrication flow through the transmission,
disassembled view parts lists and transmission
specifications. This information has been included
to provide the user with convenient reference
information published in the appropriate vehicle
Service Manuals. Since component parts lists and
specifications may change over time, this
information should be verified with Service
Manual information.

Figure 1

5

UNDERSTANDING THE GRAPHICS

Figure 2

The flow of transmission fluid starts in the bottom
pan and is drawn through the filter, main case valve
body, main case, adapter case and into oil pump
assembly. This is a general route for fluid to flow
that is more easily understood by reviewing the illustrations provided in Figure 2. However, fluid may
pass between these and other components many times
before reaching a valve or applying a clutch. For this
reason, the graphics are designed to show the exact
location where fluid passes through a component
and into other passages for specific gear range operation.
To provide a better understanding of fluid flow in the
Hydra-matic 4L30-E transmission, the components
involved with hydraulic control and fluid flow are
illustrated in three major formats. Figure 3 provides
an example of these formats which are:

6

•

A three dimensional line drawing of the
component for easier part identification.

•

A two dimensional line drawing of the component
to indicate fluid passages and orifices.

•

A graphic schematic representation that displays
valves, checkballs, orifices and so forth, required
for the proper function of transmission in a specific
gear range. In the schematic drawings, fluid
circuits are represented by straight lines and
orifices are represented by indentations in a circuit.
All circuits are labeled and color coded to provide
reference points between the schematic drawing
and the two dimensional line drawing of the
components.

•

Figure 4 (page 7A) provides an illustration of a
typical valve, bushing and valve train components.
A brief description of valve operation is also
provided to support the illustration.

•

Figure 5 (page 7A) provides a color coded chart
that references different fluid pressures used to
operate the hydraulic control systems. A brief
description of how fluid pressures affect valve
operation is also provided.

UNDERSTANDING THE GRAPHICS
OIL PUMP ASSEMBLY (10)
CO
RE NV IN
LE
AS
E
E
CO X
O
AP LER
P
LIN LY
E

ADAPTER CASE SIDE
NV

CL

CO

NT

LINE

RO

L

CAPILLARY
RESTRICTION

➤

THROTTLE SIGNAL

EX

CO

SOLENOID SIGNAL

TO

CONVERTER HOUSING SIDE

PUMP
ASSEMBLY
(10)

EX
THROTTLE SIGNAL
ACCUMULATOR
ASSEMBLY
(214-217)

LINE

SUCTION

TWO DIMENSIONAL

LINE

SUCTION

LINE

EX

ADAPTER CASE VALVE BODY ASSEMBLY (71)
3-4 ACCUM

FORCE
MOTOR
SOLENOID
(404)
FD LIMIT

EX

3-4 ACCUM

EX

ADAPTER CASE SIDE

THROTTLE SIGNAL

THROTTLE SIG

GRAPHIC SCHEMATIC REPRESENTATION
THROTTLE SIG

THREE DIMENSIONAL

CONVERTER IN

REVERSE

THROTTLE SIGNAL

SUCTION

BOOST PRESSURE REGULATOR

EX

3-4 ACCUM CONTROL

LINE

FEED LIMIT

EX

EX

EX
LINE

LINE

FEED LIMIT
FEED LIMIT
FORCE MOTOR
SCREEN (415)

2ND CL
REV

GRAPHIC SCHEMATIC REPRESENTATION

1-2 & 3-4 SHIFT
EX

N.C.

EX

EX

SOLENOID
(303)

SERVO REL

4TH CL FEED 1
D 3 2/1-2

SOLENOID
(307)

CONTROL 1-2 ACCUM

2-3 SHIFT
EX
4TH CL FD 1

EX
SERVO REL
D32
EX

N.O.

EX
EX

SERVO APPLY
BAND
CONTROL
SOLENOID
PWM
(323)

D 3 2/1-2

EX

1-2 REG

D 3 2/1-2
1-2 ACCUM

EX

EX

EX

D 3 2/1-2

SERVO REL

1-2 ACC

4TH CL FEED 2

MAIN CASE SIDE

EX

1-2 REG
3RD CL FD

MAIN CASE VALVE BODY ASSEMBLY (84)

THROTTLE SIGNAL

TWO DIMENSIONAL

2ND CLUTCH
D 3 2/1-2

THREE DIMENSIONAL

SOLENOID FEED

CONVERTER
CLUTCH
SOLENOID
(416)

SOLENOID SIGNAL

EX

D 3 2/1-2
D32

D32

EX

1-2 REG

1-2

LOW PRESSURE
PWM SOLENOID
SCREEN (324)

1-2

D32
D32

THREE DIMENSIONAL

GASKET
(88)

TRANSFER
PLATE
(87)

TWO DIMENSIONAL

GASKET
(86)

EX

1-2

EX

LINE
R321
1-2

REV

P RN D 3 2 1

R321
REVERSE

MANUAL VALVE

GRAPHIC SCHEMATIC REPRESENTATION
UNRESTRICTED
PASSAGE

MAIN CASE VALVE BODY SIDE
SPACER PLATE
GASKET

GASKET
➤

➤

➤

➤

ORIFICE IN
TRANSFER
PLATE
➤

THREE DIMENSIONAL

TWO DIMENSIONAL

Figure 3

GRAPHIC SCHEMATIC REPRESENTATION

FOLDOUT ➤

7

HYDRA-MATIC 4L30-E

CONVERTER
HOUSING
(6)

CONVERTER
CLUTCH ASSEMBLY
(1)
TURBINE
SHAFT
(506)

3RD CLUTCH
PLATE ASSEMBLY
(641-643)

OVERDRIVE CLUTCH OVERDRIVE COMPLETE
ROLLER ASSEMBLY
CARRIER ASSEMBLY
2ND CLUTCH
(516)
(525)
PLATE ASSEMBLY
(625-627)
OIL PUMP
OVERRUN
ASSEMBLY
MAIN
CLUTCH PLATE
(10)
REVERSE CLUTCH
CASE
ASSEMBLY
PLATE ASSEMBLY
(36)
(520-523)
ADAPTER
(614-616)
CASE
(20)

PRINCIPLE
SPRAG CAGE
ASSEMBLY
(650)

OUTPUT
SHAFT
(653)

EXTENSION
ASSEMBLY
(43)

DRIVE
FLANGE
(49)
SPEED
SENSOR
ASSEMBLY
(45)

SPEEDO
WHEEL
(672)
SPEEDO
WHEEL
GEAR
(671)
BAND
ASSEMBLY
(664)
PLANETARY
CARRIER
ASSEMBLY
(653)
SERVO
PISTON
(97)
SELECTOR
LEVER
(60)
CENTER
SUPPORT
(30)

STATOR
TURBINE
ASSEMBLY
PRESSURE
PLATE

8

SOLENOID
ASSEMBLY
(416)
CONVERTER
PUMP
ASSEMBLY

MAIN CASE
VALVE BODY
ASSEMBLY
(84)
4TH CLUTCH
PLATE ASSEMBLY
(502 & 503)

ADAPTER CASE
VALVE BODY
ASSEMBLY
(71)

Figure 6

GENERAL DESCRIPTION
The Hydra-matic 4L30-E is a fully automatic, four
speed, front wheel drive transmission. It consists primarily of a four-element torque converter, two planetary
gear sets, various clutches, an oil pump, and a control
valve body.
The four-element torque converter contains a pump, a
turbine, a pressure plate splined to the turbine, and a
stator assembly. The torque converter acts as a fluid
coupling to smoothly transmit power from the engine
to the transmission. It also hydraulically provides additional torque multiplication when required. The pressure
plate, when applied, provides a mechanical “direct
drive” coupling of the engine to the transmission.
The two planetary gear sets provide the four forward
gear ratios and reverse. Changing of the gear ratios is
fully automatic and is accomplished through the use of
various electronic powertrain sensors that provide input signals to the Transmission Control Module (TCM).
The TCM interprets these signals to send current to the
various solenoids inside the transmission.

By using electronics, the TCM controls shift points,
shift feel and torque converter clutch apply and release, to provide proper gear ranges for maximum fuel
economy and vehicle performance.
Five multiple-disc clutches, one roller clutch, a sprag
clutch, and a brake band provide the friction elements
required to obtaain the various ratios with planetary
gear sets.
A hydraulic system (the control valve body), pressurized by a gear type pump provides the working pressure
needed to operate the friction elements and automatic
controls.
Several electronic solenoids and sensors in the powertrain work in conjunction with the vehicle’s
Transmission Control Module (TCM), to control various shift points, shift feel and converter clutch apply
and release.

EXPLANATION OF GEAR RANGES

P

R

N

D

3

2

1

Figure 8

The transmission can be operated in any one of the
seven different positions shown on the shift quadrant
(Figure 8).
P – Park position enables the engine to be started while
preventing the vehicle from rolling either forward or
backward. For safety reasons, the vehicle’s parking
brake should be used in addition to the transmission
“Park” position. Since the output shaft is mechanically
locked to the case through the parking pawl and parking lock wheel, Park position should not be selected
until the vehicle has come to a complete stop.
R – Reverse enables the vehicle to be operated in a
rearward direction.
N – Neutral position enables the engine to start and
operate without driving the vehicle. If necessary, this
position should be selected to restart the engine while
the vehicle is moving.
D – Drive range should be used for all normal driving
conditions for maximum efficiency and fuel economy.
Drive range allows the transmission to operate in each
of the four forward gear ratios. When operating in the
Drive range, shifting to a lower or higher gear ratio is

accomplished by depressing the accelerator or by manually selecting a lower gear with the shift selector.
It is not recommended that the transmission be operated in Drive range when pulling heavy loads or driving on extremely hilly terrain. Typically these conditions
put an extra load on the engine, therefore the transmission should be driven in a lower manual gear selection
for maximum efficiency.
3 – Manual Third should be used when driving conditions dictate that it is desirable to use only three gear
ratios. These conditions include towing a trailer or driving on hilly terrain as described above. Automatic shifting is the same as in Drive range for first, second and
third gears except the transmission will not shift into
Fourth gear.
2 – Manual Second adds more performance for congested traffic or hilly terrain. It has the same starting
ratio (first gear) as Manual Third but the transmission
is prevented from shifting above second gear. Manual
Second can be selected at any vehicle speed therefore,
it is commonly used for acceleration or engine braking
as required.
1 – Manual First can also be selected at any vehicle
speed, however if the transmission is in third or fourth
gear it will immediately shift into second gear. When
the vehicle speed slows to below approximately 60
km/h (37 mph) the transmission will then shift into
first gear. This is particularly beneficial for maintaining maximum engine braking when descending steep
grades.

FOLDOUT ➤ 9

MAJOR MECHANICAL COMPONENTS
TURBINE
SHAFT
(506)

ADAPTER
CASE
(20)

MAIN
CASE
(36)

4TH CLUTCH
ASSEMBLY
(501-503,530-534)

SPLINED
TOGETHER

REVERSE
CLUTCH
ASSEMBLY
(608-617)

2ND CLUTCH
ASSEMBLY
(618-629)

SPRAG CLUTCH
ASSEMBLY
(650)

INPUT
SUN GEAR
ASSEMBLY
(646)

3RD CLUTCH
ASSEMBLY
(634-643)

OVERDRIVE
INTERNAL
GEAR
(528)

OVERDRIVE
CARRIER
ASSEMBLY
(525)

SOME MODELS
SPLINED
TOGETHER

PARKING LOCK
WHEEL
(668)

SPEEDO
WHEEL
(672)

SPEEDO
WHEEL
GEAR
(671)

REACTION
SUN GEAR
(658)

OVERDRIVE
SUN GEAR
(519)
BRAKE BAND
ASSEMBLY
(664)

OVERRUN
CLUTCH
ASSEMBLY
(510-524)
RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

SPLINED TO
RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

PARKING LOCK
ACTUATOR
ASSEMBLY
(56)
REACTION
SUN DRUM
(659)
SPLINED TO
PARKING
LOCK
WHEEL
(668)

10

SPLINED TO
SPEEDO
WHEEL
(672)

SERVO
ASSEMBLY
(90-103)

Figure 9

PARKING LOCK
PAWL
(54)

COLOR LEGEND

RANGE REFERENCE CHART

COLOR LEGEND

MAJOR MECHANICAL COMPONENTS

APPLY COMPONENTS

The foldout graphic on page 10 contains a disassembled drawing of the major components used in the Hydra-matic 4L30-E
transmission. This drawing, along with the cross sectional illustrations on page 8 and 8A, show the major mechanical components and their relationship to each other as a complete assembly.
Therefore, color has been used throughout this book to help
identify parts that are splined together, rotating at engine speed,
held stationary, and so forth. Color differentiation is particularly helpful when using the Power Flow section for understanding the transmission operation.

The Range Reference Chart on page 11, provides another valuable source of information for explaining the overall function of
the Hydra-matic 4L30-E transmission. This chart highlights the
major apply components that function in a selected gear range,
and the specific gear operation within that gear range.

The color legend below provides the “general” guidelines that
were followed in assigning specific colors to the major components. However, due to the complexity of this transmission,
some colors (such as grey) were used for artistic purposes rather
than based on the specific function or location of that component.

Included as part of this chart is the same color reference to each
major component that was previously discussed. If a component
is active in a specific gear range, a word describing its activity
will be listed in the column below that component. The row
where the activity occurs corresponds to the appropriate transmission range and gear operation.

• •

An abbreviated version of this chart can also be found at the top
of the half page of text located in the Power Flow section. This
provides for a quick reference when reviewing the mechanical
power flow information contained in that section.

•
•

Components held stationary in the case or splined to
the case. Examples: Oil Pump Assembly (10), 4th
Clutch Piston (532), Center Support (30) and Brake
Band Assembly (664).

•

•

•
•

Components that rotate at engine speed. Examples:
Torque Converter Cover and Pump, and the Oil Pump
Gears.
Components that rotate at turbine speed. Examples:
Converter Turbine, Pressure Plate, Turbine Shaft
(506) and Overdrive Carrier Assembly (525).
Components that rotate at transmission output speed
and other components. Examples: Ravigneaux Carrier and Output Shaft Assembly (653), Parking Lock
Wheel (668), Speedo Wheel (672) and Drive Flange
(44).
Components such as the Stator in the Torque Converter (1), Overrun Clutch Housing (510) and Input
Sun Gear Assembly (646).
RANGE

Components such as the Overdrive Internal Gear
(528) and 3rd Clutch Drum Assembly (634).

1-2 / 3-4
SOL
N.C.

2-3
SOL
N.O.

OVERDRIVE OVERRUN
ROLLER
CLUTCH
CLUTCH

OFF

ON

APPLIED

REVERSE

OFF

ON

LD

APPLIED

1st

OFF

ON

LD

APPLIED

2nd

ON

ON

LD

APPLIED

3rd

ON

OFF

LD

APPLIED

4th

OFF

OFF

FW

1st

OFF

ON

LD

APPLIED

2nd

ON

ON

LD

APPLIED

3rd

ON

OFF

LD

APPLIED

APPLIED

1st

OFF

ON

LD

APPLIED

APPLIED

2nd

ON

ON

LD

APPLIED

1st

OFF

ON

LD

APPLIED

GEAR

P-N
Components such as the 2nd Clutch Drum (618)
and Ring Gear (630).

R

All bearings, bushings, gaskets and spacer plates.

D
All seals

3
2
1

LD = LOCKED IN DRIVE

10A

10B

FW = FREEWHEELING

FOURTH
CLUTCH

THIRD
CLUTCH

REVERSE
CLUTCH

SECOND
CLUTCH

PRINCIPLE
BAND
ENGINE
SPRAG ASSEMBLY BRAKING
ASSEMBLY
NO

APPLIED

LD

NO

LD

APPLIED

NO

APPLIED

FW

APPLIED

YES

APPLIED

APPLIED

NE

YES

APPLIED APPLIED

APPLIED

NE

YES

LD

APPLIED

NO

APPLIED

FW

APPLIED

YES

APPLIED

NE

APPLIED
APPLIED

YES

LD

APPLIED

YES

FW

APPLIED

YES

LD

APPLIED

YES

NE = NOT EFFECTIVE

Figure 10

11

TORQUE CONVERTER

DAMPER
ASSEMBLY
(D)
PRESSURE PLATE
ASSEMBLY
(C)

The torque converter (1) is the primary component for
transmittal of power between the engine and the transmission. It is bolted to the engine flywheel (also known
as the flexplate) so that it will rotate at engine speed.
The major functions of the torque converter are:
• to provide a fluid coupling for a smooth
conversion of torque from the engine to the mechanical components of the transmission.
• to multiply torque from the engine which
enables the vehicle to achieve additional
performance when required.
• to mechanically operate the transmission oil
pump (4) through the converter hub.
• to provide a mechanical link, or direct drive, from
the engine to the transmission through the use of
the torque converter clutch (TCC), or pressure
plate (C).
The torque converter assembly consists of
the following five main sub-assemblies:
• a converter housing cover assembly
(A) which is bolted to the engine
flywheel and is welded to the
converter pump assembly (I).
• a converter pump assembly (I)
which is the driving member.
• a turbine assembly (F) which is
the driven or output member.
• a stator assembly (H) which is the
reaction member located between the
converter pump and turbine assemblies.
• a pressure plate assembly (C) splined
to the turbine assembly to provide a
mechanical direct drive when appropriate.

CONVERTER PUMP ASSEMBLY AND
TURBINE ASSEMBLY
When the engine is running the converter pump assembly acts as a centrifugal pump by picking up fluid
at its center and discharging it at its rim between the
blades (see Figure 12). The force of this fluid then hits
the turbine blades and causes the turbine to rotate. The
turbine shaft (506) is splined to the converter turbine
to provide the input to the transmission. As the engine
and converter pump increase in RPM, so does the
turbine assembly and turbine shaft. However, with the
pressure plate released, turbine speed does not equal
engine speed due to the small amount of slip that
occurs in a fluid coupling.

TURBINE
ASSEMBLY
(F)

THRUST
BEARING
ASSEMBLY
(G)

STATOR
ASSEMBLY
(H)

CONVERTER PUMP
ASSEMBLY
(I)

TORQUE
CONVERTER
ASSEMBLY
(1)

TCC
RELEASED

F

RELEASE
FLUID

H

➤
➤
➤
➤

RELEASE
FLUID

STATOR
SHAFT
(209)

B

E
TURBINE
SHAFT
(506)

APPLY
FLUID

D
G

➤
➤

APPLY
FLUID

➤

TORQUE CONVERTER:

12

THRUST
BEARING
ASSEMBLY
(G)

➤

CONVERTER HOUSING
COVER ASSEMBLY
(A)

PRESSURE
PLATE
SPRING
(E)

TCC
APPLIED
C

➤

TURBINE
THRUST
SPACER
(B)

I
A

Figure 11

TORQUE CONVERTER
PRESSURE PLATE, DAMPER AND
CONVERTER HOUSING ASSEMBLIES
The pressure plate is splined to the turbine hub and applies (engages) with the
converter cover to provide a mechanical coupling of the engine to the transmission. When the pressure plate assembly is applied, the small amount of slippage
that occurs through a fluid coupling is eliminated, thereby providing a more
efficient transfer of engine torque to the transmission and drive wheels. The
bottom half of the cutaway view of the torque converter in Figure 11 shows the
pressure plate in the apply position while the top half shows the released
position. Refer to Torque Converter Release and Apply on pages 54 and 55 for
an explanation of hydraulic control of the torque converter clutch.

To reduce torsional shock during the apply of the pressure plate to the converter cover, a spring loaded damper assembly (D) is used. The damper assembly is splined to the turbine assembly and the damper’s pivoting mechanism is
attached to the pressure plate assembly. When the pressure plate applies, the
pivoting mechanism allows the pressure plate to rotate independently of the
damper assembly up to approximately 45 degrees. The cushioning effect of the
damper assembly springs aid in reducing converter clutch apply feel and irregular torque pulses from the engine or road surface.

FLUID FLOW

STATOR
ASSEMBLY
(H)
TURBINE
ASSEMBLY
(F)

CONVERTER PUMP
ASSEMBLY
(I)

Figure 12
STATOR ASSEMBLY
STATOR

STATOR HELD
FLUID FLOW REDIRECTED

CONVERTER
MULTIPLYING

The stator assembly (or assemblies, see page 14) is
located between the pump assembly and turbine
assembly and is mounted on a roller clutch. The
roller clutch is a type of one-way clutch that prevents the stator from rotating in a counterclockwise
direction. The function of the stator is to redirect
fluid returning from the turbine which assists the
engine in turning the converter pump assembly,
thereby multiplying torque.
At low vehicle speeds, when greater torque is
needed, fluid from the turbine hits the front side of
the stator blades (converter multiplying torque).
The roller clutch prevents the stator from rotating
in the same direction as the fluid flow, thereby
redirecting the fluid and increasing the fluid force
on the pump assembly. Fluid from the converter
pump then has more force to turn the turbine assembly and multiply engine torque.

FLUID FLOW
FROM TURBINE

CONVERTER AT
COUPLING SPEED
STATOR ROTATES
FREELY

Figure 13

As vehicle speed increases, centrifugal force
changes the direction of fluid leaving the turbine
such that it hits the back side of the stator blades
(converter at coupling speed). When this occurs,
the stator overruns the roller clutch and rotates
freely. Fluid is no longer redirected and torque is
no longer multiplied.

13

APPLY COMPONENTS
The Apply Components section is designed to
explain the function of the hydraulic and
mechanical holding devices used in the Hydramatic 4L30-E transmission. Some of these apply
components, such as clutches and a band, are
hydraulically “applied” and “released” in order to
provide automatic gear range shifting. Other
components, such as a roller clutch or sprag clutch,
often react to a hydraulically “applied” component
by mechanically “holding” or “releasing” another
member of the transmission. This interaction
between the hydraulically and mechanically
applied components is then explained in detail
and supported with a graphic illustration. In
addition, this section shows the routing of fluid
pressure to the individual components and their
internal functions when it applies or releases.

The sequence in which the components in this
section have been discussed coincides with their
physical arrangement inside the transmission. This
order closely parallels the disassembly sequence
used in the Hydra-matic 4L30-E Unit Repair
Section of the appropriate Service Manual. It also
correlates with the components shown on the
Range Reference Charts that are used throughout
the Power Flow section of this book. The
correlation of information between the sections of
this book helps the user more clearly understand
the hydraulic and mechanical operating principles
for this transmission.

Figure 14

15

APPLY COMPONENTS
OVERRUN CLUTCH:
The overrun clutch assembly is located in the overrun clutch housing (510)
inside the adapter case (20). The external teeth on the steel clutch plates
(521) are splined to the overrun clutch housing while the internal teeth on
the fiber clutch plates (522) are splined to the overdrive carrier assembly
(525). The overrun clutch is applied as soon as the engine is started and in
all gear ranges except Drive Range - Fourth Gear.

OVERRUN
CLUTCH
HOUSING
(510)

OVERRUN CLUTCH CHECKBALL
APPLIED
RELEASED

➤ ➤

When fully applied, the steel plates (521) and fiber plates (522)
are locked together, thereby holding the overrun clutch housing
and overdrive carrier assembly together. This forces the housing,
overdrive sun gear (519) which is splined to the housing’s inner
hub, and carrier to rotate at the same speed.

OVERRUN CLUTCH RELEASE:
To release the overrun clutch, overrun clutch fluid exhausts from
the housing and back through the turbine shaft and oil pump hub,
thereby decreasing fluid pressure at the overrun clutch piston
(513). Without fluid pressure, spring force from the waved release spring (514) moves the overrun clutch piston away from
clutch pack. This disengages the steel and fiber clutch plates from
the backing plate (523) and disconnects the overrun clutch housing (510) from the overdrive carrier (525).

16

515

517

518

519

SNAP
RING
(524)

OVERRUN
CLUTCH
HOUSING
(510)

RETAINER
(515)
CAM
(517)

RELEASE
SPRING
(514)

OVERRUN
CLUTCH
APPLY
FLUID

SUN
GEAR
(519)
SNAP
RING
(518)
OVERRUN
CLUTCH
STEEL PLATE
(521)

Note: Some models use a waved plate (520) to help control the
overrun clutch apply feel.

514

EX

OVERRUN
CLUTCH
PISTON
(513)

During the exhaust of overrun clutch fluid, the overrun clutch
checkball unseats (see illustration). Centrifugal force, resulting
from the overrun clutch housing rotating, forces residual overrun
clutch fluid to the outside of the piston housing and past the
unseated checkball. If this fluid did not completely exhaust from
behind the piston there could be enough pressure for a partial
apply, or drag, of the overrun clutch plates.

513

➤

To apply the overrun clutch, overrun clutch fluid is fed through
the oil pump hub, into the turbine shaft (506) and to the inner hub
of the overrun clutch housing. Feed holes in the inner hub allow
fluid to enter the housing behind the overrun clutch piston (513).
Overrun clutch fluid pressure seats the overrun clutch checkball
(located in the housing) and moves the piston to compress the
waved release spring (514) which cushions the clutch apply. As
fluid pressure increases, the piston compresses the steel and fiber
clutch plates together until they are held against the overrun
clutch backing plate (523). The increase in fluid pressure forces
any air in the overrun clutch fluid circuit to exhaust past the
checkball, before it fully seats, to prevent excess cushion during
the clutch apply.

➤➤➤

OVERRUN CLUTCH APPLY:

SOME MODELS
520

Figure 15

521

522

OVERRUN
CLUTCH
LINED PLATE
(522)

OVERRUN
CLUTCH
BACKING PLATE
(523)

523

524

APPLY COMPONENTS

516

504

TURBINE OIL SEAL
RING
SHAFT
(508)
(506)

506

505

OVERDRIVE
ROLLER
CLUTCH
(516)

OVERDRIVE
CARRIER
ASSEMBLY
(525)
LUBE
PASSAGE

508

525

526

OVERRUN
CLUTCH
APPLY
FLUID

SNAP
RING
(526)

OVERDRIVE ROLLER CLUTCH:

OVERRUN
CLUTCH
PLATE
OVERDRIVE
ROLLER CLUTCH (521-522)
(516)
HOLDING

OVERDRIVE
CARRIER
ASSEMBLY
(525)

The overdrive roller clutch assembly (516) is located between the overdrive
carrier assembly (525) and overrun clutch housing (510). The outer race of
the roller clutch is pressed into the overdrive carrier while the roller clutch
inner cam (517) is splined to the inner hub of the overrun clutch housing.
The overdrive roller clutch is a type of one-way clutch that prevents the
overrun clutch housing from rotating clockwise faster than the overdrive
carrier. This assists the overrun clutch in holding the overrun clutch housing and overdrive carrier together. The overdrive roller clutch is holding,
and effective, during acceleration in all gear range except Drive Range EXAMPLE "A" Fourth Gear, the same as the overrun clutch.
DIRECT DRIVE

ROLLER CLUTCH HOLDING: (EXAMPLE "A") DIRECT DRIVE
OVERDRIVE
INTERNAL
GEAR
(528)

G
TIN
TA

➤

➤

RO

ING
AT
T
RO

OVERRUN CLUTCH HOUSING
AND SUN GEAR (INNER CAM)

(OUTER RACE)

OVERRUN
CLUTCH
PLATE
OVERDRIVE
ROLLER CLUTCH (521-522)
(516)
OVERRUNING

OVERDRIVE
CARRIER
ASSEMBLY
(525)

EXAMPLE "B"
OVERDRIVE The roller clutch releases when the overdrive carrier rotates clockwise
faster than the overrun clutch housing. This causes the rollers to ‘move
down the ramp’ on the inner cam (517) and rotate freely between the inner
cam and outer race. This action occurs in Fourth gear when the overrun
OVERDRIVE
clutch is released and the 4th clutch is applied to hold the overrun clutch
INTERNAL
housing (510) and overdrive sun gear (519) stationary to the adapter case.
GEAR
As torque from the engine drives the carrier clockwise, the roller clutch
(528)
outer race in the carrier overruns the roller clutch. The pinion gears rotate
clockwise on their pins and walk around the stationary sun gear, thereby
driving the overdrive internal gear (528) in a Fourth gear overdrive gear
ratio of approximately .73:1.

Coast Conditions:

D
EL

➤

H

➤

With the sun gear and overdrive carrier rotating at the same speed, the
pinion gears do not rotate on their pins but act as wedges and drive the
overdrive internal gear. This creates a 1:1 gear ratio through the overdrive
planetary gear set. Remember that, as explained above, the roller clutch is
assisting the overrun clutch which is also applied and holding the carrier
and overrun clutch housing together.

ROLLER CLUTCH RELEASED: (EXAMPLE "B") OVERDRIVE

ING
AT
T
RO

(OUTER RACE)

When the 4th clutch is released the overrun clutch housing is free to rotate.
The overdrive carrier pinion gears are in mesh with both the overdrive sun
gear (519), which is splined to the inner hub of the overrun clutch housing,
and the overdrive internal gear (528). Power from the engine drives the
overdrive carrier clockwise. Vehicle load holding the overdrive internal
gear causes the pinion gears to attempt to rotate counterclockwise on their
pins around the internal gear as the travel clockwise with the carrier assembly. Therefore, the pinion gears attempt to drive the sun gear clockwise,
faster than the carrier assembly is rotating. However, this causes the rollers
to ‘move up the ramp’ on the inner cam (517) and wedge between the inner
cam and outer race, thereby locking the overrun clutch housing (510) and
overdrive carrier together.

OVERRUN CLUTCH HOUSING
AND SUN GEAR (INNER CAM)

When the throttle is released and the vehicle is decelerating, power from
vehicle speed drives the transmission’s output shaft and gear sets faster
than engine torque is driving. In gear ranges when the overrun clutch is
applied and engine compression braking slows the vehicle during coast
conditions, the overdrive roller clutch is not holding. However, the overdrive carrier does not overrun the roller clutch because the overrun clutch
holds the carrier and overrun clutch housing together.

Figure 16

17

APPLY COMPONENTS
4TH CLUTCH:
ADAPTER
CASE
(20)

The 4th clutch assembly is located in the adapter case. The external teeth on the
steel clutch plates (502) are splined to the adapter case while the internal teeth on
the fiber clutch plates (503) are splined to the outside of the overrun clutch
housing (510). The 4th clutch is only applied in Drive Range - Fourth Gear to
provide an overdrive gear ratio through the overdrive planetary gear set.

ADAPTER
CASE
(20)

4TH CLUTCH
STEEL PLATE
(502)

4TH CLUTCH
LINED PLATE
ASSEMBLY
(503)

SNAP RETAINER 4TH CLUTCH
RING & SPRING
PISTON
(530) ASSEMBLY
(532)
(531)

4TH CLUTCH
RETAINER
(501)

SEAL
(OUTER)
(534)

4TH CLUTCH APPLY:
To apply the 4th clutch, 4th clutch fluid is fed
from the center support (30) into the adapter
case behind the 4th clutch piston (532). 4th
clutch fluid pressure moves the piston to compress the retainer and spring assembly (531)
which cushions the clutch apply. As fluid pressure increases, the piston compresses the steel
and fiber clutch plates until they are held against
the 4th clutch retainer (501). The 4th clutch
retainer is splined to the adapter case and held
in place by the oil pump assembly (10). The
retainer functions as a backing plate for the
clutch pack.

SEAL
(INNER)
(533)

When fully applied, the steel and fiber clutch
plates are locked together and held stationary to
the adapter case. The internal teeth on the fiber
clutch plates (503) hold the overrun clutch housing (510) stationary. This prevents the overdrive
sun gear (519), which is splined to the overrun
clutch housing’s inner hub, from rotating.

4TH CLUTCH RELEASE:
To release the 4th clutch, 4th clutch fluid exhaust from the adapter case and back through
the center support (30), thereby decreasing fluid
pressure at the 4th clutch piston (532). Without
fluid pressure, spring force from the piston
spring assembly (531) moves the 4th clutch piston away from the clutch pack. This disengages
the steel and fiber clutch plates from the 4th
clutch retainer (501) and allows the overrun
clutch housing and overdrive sun gear to rotate
freely.

4TH CLUTCH
APPLY
FLUID
501

18

502

503

530

531

Figure 17

532

533

534

APPLY COMPONENTS
MAIN
CASE
(36)

MAIN
CASE
(36)

REVERSE CLUTCH APPLIED:
To apply the reverse clutch, reverse clutch fluid is fed
from the center support into the cavity behind the reverse clutch piston (610). Reverse clutch fluid pressure
moves the piston to compress the piston spring assembly (611) which cushions the clutch apply. As fluid pressure increases, the piston compresses the steel and fiber
clutch plates together until they are held against the
selective reverse clutch pressure plate (617). The pressure plate, which is selective for assembly purposes, is
held stationary by the main case and functions as a
backing plate for the clutch pack. Also included in the
reverse clutch assembly is a steel waved plate (614) that,
in addition to the spring assembly (611), helps cushion
the reverse clutch apply.

REVERSE CLUTCH:
The reverse clutch is located in the main transmission case (31) directly
behind the center support (604). The external teeth on the steel clutch
plates (615) are splined to the main case while the internal teeth on the
fiber clutch plates (616) are splined to the outside of the 2nd clutch drum
(618). The reverse clutch is only applied when the gear selector lever is in
the Reverse (R) position.

CENTER
SUPPORT
ASSEMBLY
(30)

REVERSE CLUTCH
WAVED PLATE
(614)

REVERSE CLUTCH
LINED PLATE
(616)

REVERSE CLUTCH
STEEL PLATE
(615)

SEAL
(OUTER)
(609)

REVERSE CLUTCH
PRESSURE/SELECTIVE
PLATE
(617)

REVERSE
CLUTCH
PISTON
(610)
SPRING
SEAT
(612)

SEAL
(INNER)
(608)

RETAINING
RING
(613)

When fully applied, the steel clutch plates (615), fiber
clutch plates (616) and waved plate (614) are locked
together and held stationary to the main case. The internal teeth on the fiber clutch plates hold the 2nd clutch
drum (618) and ring gear (630) stationary.

REVERSE CLUTCH RELEASE:
To release the reverse clutch, reverse clutch fluid pressure exhausts from the reverse clutch piston (610) and
center support. Without fluid pressure, spring force from
the piston spring assembly (611) and waved plate (614)
moves the reverse clutch piston away from the clutch
pack. This disengages the steel plates, fiber plates and
waved plate from the pressure plate (617) and allows the
2nd clutch drum and ring gear to rotate freely.

30

608

31

609

12

610

OIL
SEAL
RINGS
(32)
PISTON
CLUTCH
SPRING
(611)

32

611

612

613

Figure 18

614

615

616

617

19

APPLY COMPONENTS
2ND CLUTCH:
The 2nd clutch assembly is located in the 2nd clutch drum (618) inside the main transmission case (31).
The external teeth on the steel clutch plates (626) are splined to the 2nd clutch drum while the internal teeth
on the fiber clutch plates (627) are splined to the 3rd clutch drum assembly (634). The 2nd clutch is applied
when the transmission is in Second, Third and Fourth gears.

2ND CLUTCH APPLY:
To apply the 2nd clutch, 2nd clutch fluid is fed through the center support (604), into the intermediate shaft
which is connected to the 3rd clutch drum, and to the inner hub of the 2nd clutch drum. Feed holes in the
inner hub allow fluid to enter the drum behind the 2nd clutch piston (622). 2nd clutch fluid pressure seats
the 2nd clutch checkball (located in the drum) and moves the piston to compress the piston spring assembly
(611) which cushions the clutch apply. As fluid pressure increases, the piston compresses the steel and fiber
clutch plates together until they are held against the 2nd clutch spacer (628). The spacer is splined to the
2nd clutch drum and held in place by the retainer ring (629). The spacer functions as a backing plate for the
clutch pack. The increase in fluid pressure forces any air in the 2nd clutch fluid circuit to exhaust past the
2nd clutch checkball, before it fully seats, to prevent excess cushion during the clutch apply.

2ND CLUTCH
DRUM ASSEMBLY
(618)

2ND CLUTCH CHECKBALL
APPLIED
RELEASED

Also included in the 2nd clutch assembly is a
steel waved plate (625) that, in addition to the
spring assembly (611), helps cushion the 2nd
clutch apply. When fully applied, the steel clutch
plates (626), fiber clutch plates (627) and waved
plate are locked together, thereby holding the 2nd
clutch drum and 3rd clutch drum together. This
forces both drums and the ring gear (630), which
is splined to the 2nd clutch drum, to rotate at the
same speed.

➤

➤ ➤

➤ ➤EX

SEAL
(OUTER)
(621)

2ND
CLUTCH
WAVED
PLATE
(625)

➤

2ND
CLUTCH
STEEL
PLATE
(626)

SEAL
(INNER)
(620)

2ND
CLUTCH
SPACER
(628)
2ND
CLUTCH
LINED
PLATE
(627)

RETAINING
RING
(629)

2ND CLUTCH RELEASE:
To release the 2nd clutch, 2nd clutch fluid exhausts from the 2nd clutch drum (618) and back
through the intermediate shaft and center support
(604), thereby decreasing fluid pressure at the
2nd clutch piston (622). Without fluid pressure,
spring force from the piston spring assembly
(611) and waved plate (625) moves the 2nd clutch
piston away from the clutch pack. This disengages the steel plates, fiber plates and waved plate
from the spacer ring (628) and disconnects the
2nd and 3rd clutch drums. During the exhaust of
2nd clutch fluid, the 2nd clutch checkball unseats
(see illustration). Centrifugal force, resulting
from the 2nd clutch drum rotating, forces residual
2nd clutch fluid to the outside of the piston housing and past the unseated checkball. If this fluid
did not completely exhaust from behind the piston there could be enough pressure for a partial
apply, or drag, of the 2nd clutch plates.

620

621

622

2ND CLUTCH
APPLY
FLUID

611

2ND
CLUTCH
DRUM
ASSEMBLY
(618)
623

20

613

625

626

627

2ND
CLUTCH
PISTON
(622)

PISTON
CLUTCH
SPRING
(611)
628

Figure 19

SPRING
SEAT
(623)

629

RETAINING
RING
(624)

630

RING
GEAR
(630)

629

APPLY COMPONENTS
3RD CLUTCH:
The 3rd clutch assembly is located in the 3rd clutch drum (634) inside the
main transmission case (31). The external teeth on the steel clutch plates
(642) are splined to the 3rd clutch drum while the internal teeth on the fiber
clutch plates (643) are splined to the input sun gear assembly (646). The
3rd clutch is applied when the transmission is in Drive Range - Third and
Fourth gears. The 3rd clutch is also applied in First gear when the transmission is operating in Manual Second and Manual First to provide engine
compression braking.

3RD CLUTCH
DRUM ASSEMBLY
(634)

3RD CLUTCH APPLY:
To apply the 3rd clutch, 3rd clutch fluid is fed through the
center support (604), into the intermediate shaft which is
connected to the 3rd clutch drum, and to the inner hub of
the 3rd clutch drum. Feed holes in the inner hub allow fluid
to enter the drum behind the 3rd clutch piston (638). 3rd
clutch fluid pressure seats the 3rd clutch checkball (located
in the drum) and moves the piston to compress the piston
spring assembly (611) which cushions the clutch apply. As
fluid pressure increases, the piston compresses the steel and
fiber clutch plates together until they are held against the
sprag race assembly (647). The sprag race assembly is
splined to the 3rd clutch drum and held in place by the
sprag retainer ring (648). The sprag race functions as a
backing plate for the clutch pack. The increase in fluid
pressure forces any air in the 3rd clutch fluid circuit to
exhaust past the 3rd clutch checkball, before it fully seats,
to prevent excess cushion during the clutch apply.
Also included in the 3rd clutch assembly is a steel spring
cushion plate (641) that, in addition to the spring assembly
(611), helps cushion the 3rd clutch apply. When fully applied, the steel clutch plates (642), fiber clutch plates (643)
and spring plate (641) are locked together, thereby
holding the 3rd clutch drum and input sun gear
assembly (646) together. This forces the 3rd clutch
drum and input sun gear to rotate at the same speed.

3RD CLUTCH CHECKBALL
APPLIED

RELEASED

➤

➤ ➤

➤ ➤EX

➤

SPRAG
RACE
ASSEMBLY
(647)

SEAL
SEAL
(INNER) (OUTER)
(635)
(637)

LUBE
PASSAGE

3RD
CLUTCH
APPLY
FLUID

SPRAG RACE
RETAINING
RING
(648)

PISTON
CLUTCH
SPRING
(611)
SPRING
SEAT
(639)

3RD CLUTCH RELEASE:
To release the 3rd clutch, 3rd clutch fluid exhausts
from the 3rd clutch drum (634) and back through the
intermediate shaft and center support (604), thereby
decreasing fluid pressure at the 3rd clutch piston (638).
Without fluid pressure, spring force from the piston spring
assembly (611) and spring plate (641) moves the 3rd clutch
piston away from the clutch pack. This disengages the steel
plates, fiber plates and spring plate from the sprag race
assembly (647) and disconnects the 3rd clutch drum from
the input sun gear assembly.

LUBE
PASSAGE
3RD
CLUTCH
DRUM
ASSEMBLY
(634)

3RD
3RD
3RD
CLUTCH CLUTCH CLUTCH
PISTON SPRING
STEEL
(638)
CUSHION PLATE
PLATE
(642)
(641)

During the exhaust of 3rd clutch fluid, the 3rd clutch
checkball unseats (see illustration). Centrifugal force, resulting from the 3rd clutch drum rotating, forces residual
3rd clutch fluid to the outside of the piston housing and past
the unseated checkball. If this fluid did not completely exhaust from behind the piston there could be enough pressure for a partial apply, or drag, of the 3rd clutch plates.

635

637

638

611

639

640

641

642

Figure 20

643

RETAINING
3RD
RING
CLUTCH
(640)
LINED
PLATE
(643)

647

648

21

APPLY COMPONENTS
SPRAG CLUTCH:
The sprag clutch assembly (650) is located between the input sun gear assembly (646) and sprag race
assembly (647). The input sun gear assembly functions as the inner sprag race and is splined to the
short pinions in the Ravigneaux planetary carrier (653). The sprag race assembly functions as the
outer sprag race and is splined to the 3rd clutch drum (634). The sprag clutch is a type of one-way
clutch that prevents the 3rd clutch drum from rotating clockwise faster than the input sun gear.
Therefore, when the sprag clutch is holding it allows the 3rd clutch drum to drive the input sun gear.

INPUT
SUN GEAR
ASSEMBLY
(646)

SPRAG CLUTCH HOLDING:
In Park, Reverse, Neutral and First gears power flow drives the 3rd
clutch drum clockwise such that the sprag outer race pivots the sprags
toward their long diagonals. The length of the sprag’s long diagonal
(distance A) is greater than the distance between the inner and outer
races. This causes the sprags to ‘lock’ between the inner and outer races,
thereby allowing the 3rd clutch drum to drive the input sun gear assembly. The sun gear then transfers the power flow to the Ravigneaux
carrier and output shaft.
The sprag clutch is also holding in Third and Fourth gears, and First
gear in Manual First and Manual Second. However, in these gear ranges
the 3rd clutch is applied and connects the 3rd clutch drum and input sun
gear assembly. In this situation the sprag clutch assists the 3rd clutch in
driving the input sun gear. This locks the sprag clutch at all times,
during both acceleration and deceleration to provide engine compression braking.

SPRAG CLUTCH
HOLDING/DRIVING

➤

(OUTER RACE)
SPRAG
RACE
ASSEMBLY
(647)

(A)
➤

Note: Refer to the Power Flow section for a complete description of
power flow and operation of the sprag clutch during each gear range.
➤

(B)

SPRAG CLUTCH RELEASED:

➤

SPRAG
CAGE
ASSEMBLY
(650)

(INNER RACE)
INPUT
SUN
GEAR
(646)

SPRAG CLUTCH
OVERRUNNING

(OUTER RACE)
SPRAG
RACE
ASSEMBLY
(647)

The sprag clutch releases when the sprags pivot toward their short
diagonals. The length of the short diagonal (distance B) is less than the
distance between the inner and outer sprag races. This action occurs
when power flow drives the input sun gear clockwise faster than the 3rd
clutch drum, thereby allowing the input sun gear and inner race (646) to
overrun the sprag clutch. During acceleration the sprag clutch is only
overrun when the transmission is in Second gear.

Coast Conditions:
The sprag clutch is also overrun during coast conditions, or deceleration, in Reverse, Drive Range - First Gear and Manual Third - First
Gear. This is when power from vehicle speed drives the input sun gear
clockwise faster than engine torque drives the 3rd clutch drum (with the
3rd clutch released). In this situation, the sprag clutch inner race on the
input sun gear assembly overruns the sprags, thereby allowing the vehicle to coast freely.
SPRAG
CAGE
ASSEMBLY
(650)

SPRAG
CAGE
ASSEMBLY
(650)

(INNER RACE)
INPUT
SUN
GEAR
(646)

649

650

649

RETAINING
RING
(649)

22

LUBE
PASSAGE

Figure 21

INPUT
SUN GEAR
ASSEMBLY
(646)

APPLY COMPONENTS
SERVO ASSEMBLY AND BRAKE BAND:
The servo assembly, located in the bottom rear of the main transmission case (36), functions to apply the
brake band (664) and act as an accumulator to cushion the 3rd clutch apply. The brake band is applied when
the transmission is in First and Second gears. The brake band is held stationary in the main case and wraps
around the reaction sun drum (659). When compressed by the servo assembly the band holds the reaction
drum and reaction sun gear (658) stationary to the main case.

103

BRAKE BAND APPLY:
102

To apply the servo assembly and brake band, servo apply fluid is fed between the servo cover (91) and servo
piston (97). Servo apply fluid pressure forces the piston to compress both the servo cushion (99) and servo
return (103) springs. This action moves the servo apply rod (102) toward the band. The apply rod compresses
the brake band around the reaction sun drum and holds both the drum and reaction sun gear stationary to the
main case. During apply, the spring forces (servo cushion and servo return) acting against servo apply fluid
pressure help control the apply feel of the brake band.

101

BRAKE BAND RELEASE:
The servo assembly and brake band are held in the release position by the spring forces in Park, Neutral and
Reverse when servo apply fluid pressure is exhausted. In Third and Fourth gears they are held in the release
position by servo release fluid pressure assisting the spring forces. Servo release fluid pressure is fed between
the main case and servo piston. This fluid pressure assists the spring forces to move the servo piston and apply
rod against servo apply fluid pressure and away from the brake band. Therefore, the brake band releases and
the reaction drum and reaction sun gear are allowed to rotate freely.

100

99

3RD CLUTCH ACCUMULATION:
The servo assembly is also used as an accumulator for 3rd clutch apply. Servo release fluid pressure also
feeds the 3rd clutch fluid circuit to apply the 3rd clutch. Therefore, as servo release fluid pressure moves the
servo piston against servo apply fluid pressure, some of the initial fluid pressure that applies the 3rd clutch is
absorbed. This helps cushion the 3rd clutch apply. Refer to page 32A for a more detailed description of
accumulator function.

98

97

96
BRAKE BAND
ASSEMBLY
(664)

95
94

ANCHOR
PINS

93

92

91
MAIN
CASE
(36)

90

ADJUST
SLEEVE
(101)

SERVO APPLY
SERVO RELEASE

CUSHION
SPRING
SEAT
(100)
CUSHION
SPRING
(99)

APPLY
ROD
(102)

SERVO
PISTON
(97)

➤

➤

RETURN
SPRING
(103)

➤

SERVO PISTON
ASSEMBLY
(94-103)

RING
SEAL
(98)

Figure 22

SERVO
COVER
(91)
SERVO
SCREW
NUT
(95)

SERVO
PISTON
SCREW
(96)

MAIN CASE
BOTTOM PAN
(57)

23

PLANETARY GEAR SETS
PLANETARY GEAR SETS

Torque:

Planetary gear sets are used in the Hydra-matic 4L30-E transmission as the
primary method of multiplying the torque, or twisting force, of the engine
(known as reduction). A planetary gear set is also used to reverse the direction
of input torque, function as a coupling for direct drive, and provide an overdrive
gear ratio.

When engine torque is transferred through a gear set the output torque from the
gear set can either increase, decrease, or remain the same. The output torque
achieved depends on:

Planetary gears are so named because of their physical arrangement. All
planetary gear sets contain at least three main components:
• a sun gear at the center of the gear set,
• a carrier assembly with planet pinion gears that rotate around the sun gear
and,
• an internal ring gear that encompasses the entire gear set.
This arrangement provides both strength and efficiency and also evenly
distributes the energy forces flowing through the gear set. Another benefit of
planetary gears is that gear clash (a common occurrence in manual
transmissions) is eliminated because the gear teeth are always in mesh.
The Hydra-matic 4L30-E transmission consists of two planetary gear sets, the
overdrive and Ravigneaux gear sets. The graphics in Figure 23 show both of
these gear sets and their respective components. Figure 24 graphically explains
how the planetary gear sets are used in combination to achieve each of the
transmissions five different gear ratios.

(1) which member of the gear set provides the input torque to the gear set,
(2) which member of the gear set (if any) is held stationary,
and,
(3) which member of the gear set provides the output torque.
If output torque is greater than input torque the gear set is operating in reduction
(First, Second and Reverse gears). If output torque is less than input torque then
the gear set is operating in overdrive (Fourth gear). When output torque equals
input torque the gear set is operating in direct drive (Third gear) and all gear set
components are rotating at the same speed.

Torque vs. Speed
One transmission operating condition directly affected by input and output
torque through the gear sets is the relationship of torque with output speed. As
the transmission shifts from First to Second to Third to Fourth gear, the overall
output torque to the wheels decreases as the speed of the vehicle increases (with
input speed and input torque held constant). Higher output torque is needed
with low vehicle speed, First and Second gears, to provide the power to move
the vehicle from a standstill. However, once the vehicle is moving and the speed
of the vehicle increases, Third and Fourth gears, less output torque is required to
maintain that speed.

Ravigneaux Planetary Gear Set:
The Ravigneaux planetary gear set is unique in that it resembles a combination
of two gear sets. This gear set consists of two sets of pinion gears (long and
short) in one planetary carrier (653), two sun gears - input (646) and reaction
(658), and one internal ring gear (630). The short pinion gears are in constant
mesh with both the input sun gear and the long pinion gears. The long pinion
gears are also in constant mesh with the internal ring gear (630). Also, the
output shaft is connected to the Ravigneaux planetary carrier assembly (653).

ADAPTER
CASE
(20)

REDUCTION
Increasing the output torque is known as operating in reduction because there
is a decrease in the speed of the output member proportional to the increase in
output torque. Therefore, with a constant input speed, the output torque
increases when the transmission is in a lower gear, or higher gear ratio.

OVERDRIVE
INTERNAL
GEAR
(528)

OVERDRIVE
CARRIER
ASSEMBLY
(525)

OVERDRIVE
CARRIER
ASSEMBLY
(525)

OVERDRIVE
SUN GEAR
(519)

OVERDRIVE
INTERNAL
GEAR
(528)

REACTION
SUN GEAR
(658)

OVERRUN
CLUTCH
HOUSING
(510)

OVERDRIVE
SUN GEAR
(519)

2ND CLUTCH
DRUM ASSEMBLY
(618)

INPUT
SUN GEAR
ASSEMBLY
(646)

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

MAIN
CASE
(36)
INPUT
SUN GEAR
ASSEMBLY
(646)

REACTION
SUN GEAR
(658)

24

Figure 23

REACTION
SUN DRUM
(659)

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

RING
GEAR
(630)

PLANETARY GEAR SETS
Reduction occurs in First, Second and Reverse gears through the Ravigneaux
gear set. In each of these gears, power flow through the overdrive planetary gear
set is a 1:1 direct drive gear ratio. The overdrive carrier assembly provides the
input torque to the overdrive gear set. The overdrive sun gear (519) is splined to
the inner hub of the overrun clutch housing (510). Both of these components are
held to the overdrive carrier assembly (525) by the overrun clutch and overdrive
roller clutch. With the sun gear and carrier rotating at the same speed, the pinion
gears do not rotate on their pins but act as wedges to drive the overdrive internal
gear (528). Therefore, the entire overdrive planetary gear set rotates at the same
speed for a 1:1 gear ratio input to the Ravigneaux gear set.
In First gear, torque input to the Ravigneaux gear set is provided by the input
sun gear (646) in a clockwise direction. The input sun gear drives the short
pinion gears in the Ravigneaux carrier counterclockwise. The short pinion gears
then drive the long pinion gears in the Ravigneaux carrier in a clockwise
direction. The brake band is applied in First and Second gears and holds the
reaction sun gear (658) and reaction sun drum (659) stationary. The long pinion
gears walk clockwise around the stationary reaction sun gear. This action drives
the Ravigneaux carrier and output shaft assembly in an reduction gear ratio of
approximately 2.40:1.
In Second gear, the torque input to the Ravigneaux gear set is provided by the
ring gear (630) in a clockwise direction. The ring gear drives the long pinion
gears clockwise. The long pinion gears walk around the stationary reaction sun
gear (658) which is still held by the band. This action drives the Ravigneaux
carrier and output shaft assembly in a reduction gear ratio of approximately
1.48:1.

DIRECT DRIVE
Direct drive in a planetary gear set is obtained when any two members of the gear
set rotate in the same direction at the same speed. This forces the third member of
the gear set to rotate at the same speed. Therefore, in direct drive the output speed
of the transmission is the same as the input speed from the converter turbine.
Output speed will equal engine speed when the torque converter clutch is applied
(see Torque Converter - page 12).

Direct drive occurs in Third gear when input torque to the Ravigneaux gear set
is provided by both the input sun gear (646) and ring gear (630). This wedges
the short and long pinion gears together, preventing them from rotating on their
pins, and causes them to rotate with the input sun gear and ring gear at the same
speed. Therefore, the Ravigneaux carrier and output shaft assembly (653) are
also driven at the same speed for a 1:1 direct drive gear ratio. This combines
with the 1:1 gear ratio through the overdrive gear set for a direct drive 1:1 gear
ratio through the entire transmission.

OVERDRIVE
Operating the transmission in Overdrive allows the output speed of the
transmission to be greater than the input speed from the engine. This mode of
operation allows the vehicle to maintain a given road speed with reduced engine
speed for increased fuel economy.
Overdrive is achieved through the overdrive gear set and only occurs in Drive
Range - Fourth Gear. The 4th clutch holds theoverrun clutch housing (510) and
overdrive sun gear (519) stationary to the main transmission case. Therefore,
when input torque drives the overdrive carrier clockwise, the overdrive carrier
pinion gears walk clockwise around the stationary sun gear. These pinion gears
then drive the overdrive internal gear (528) clockwise in an overdrive gear ratio
of approximately .73:1. Power flow from the overdrive internal gear to the
output shaft is identical to Third gear, a direct drive 1:1 gear ratio, thereby
providing an overall transmission gear ratio of approximately .73:1.

REVERSE
The Ravigneaux planetary gear set reverses the direction of power flow rotation
when the reverse clutch is applied. In Reverse, input torque to the Ravigneaux
gear set is provided by the input sun gear (646) in a clockwise direction and the
ring gear (630) is held stationary. The input sun gear drives the short pinion
gears counterclockwise. With the ring gear held, the long pinion gears travel
counterclockwise around the ring gear as they are driven clockwise on their pins
by the short pinion gears. This action drives the Ravigneaux carrier and output
shaft in a counterclockwise (reverse) direction in a reduction gear ratio of
approximately 2.00:1.

OVERDRIVE PLANETARY GEARSET
(DIRECT DRIVE)

OVERDRIVE PLANETARY GEARSET
(OVERDRIVE)

HELD

REVERSE

FIRST

HELD

FOURTH

➤

➤

HELD

(REDUCTION)

THIRD

➤

SECOND

➤

➤

HELD

(REDUCTION)

(REDUCTION)

Figure 24

(DIRECT DRIVE)

25

HYDRAULIC CONTROL COMPONENTS
HYDRAULIC CONTROL COMPONENTS
The previous sections of this book described the operation of the major
mechanical components used in the Hydra-matic 4L30-E. This section
provides a detailed description of the individual components used in the
hydraulic system. These hydraulic control components apply and release the various clutches, band and accumulators that provide for the
automatic shifting of the transmission.

6

9
8

5

CRESCENT
DRIVEN
GEAR
(202)

209 (10)

DRIVE
GEAR
(201)

PUMP
ASSEMBLY
(10)
➤

➤

202

LINE
201

OUTLET

➤
➤

INTAKE

BOTTOM PAN
(74)

➤

SUCTION

FILTER
(79)

OIL PUMP ASSEMBLY
The oil pump assembly contains a positive displacement internal-external gear type pump located in the oil pump body (209). This spur gear
type pump consists of a drive gear (201) that has gear teeth in constant
mesh with the teeth on one side of the pump driven gear (202). Also, the
notch on the inside of the drive gear is keyed to the torque converter
pump hub. Therefore, whenever the engine is cranking, or running, the
converter pump hub drives the pump drive gear at engine speed. The
drive gear then drives the driven gear at engine speed.
On the opposite side of the mesh point between the drive and driven
gears the pump gears are separated by the crescent section of the pump
body (209). As the gears rotate toward the crescent, the volume between
the gear teeth increases and fluid volume is positively displaced, thereby
creating a vacuum at the pump intake port. This vacuum allows the
higher atmospheric pressure acting on the fluid in the main case bottom
pan (74) to force fluid through the filter assembly (79) and into the
suction side of the oil pump.

Through the rotation of the gears the gear teeth carry the fluid past the
crescent to the pressure side of the oil pump. Past the crescent the gear
teeth begin to mesh again and the volume between the gear teeth decreases. Decreasing this volume pressurizes and forces the fluid through
the pump outlet and into the line fluid circuit. This fluid is directed to
the pressure regulator valve where the fluid pressure is regulated to
maintain the required supply and pressure for the various hydraulic
circuits and apply components throughout the transmission.
As engine speed (RPM) increases, the volume of fluid being supplied
by the oil pump also increases because of the faster rotation of the
pump gears. At a specified calibrated pressure (which varies with transmission model) the pressure regulator valve allows excess fluid to return to the suction side of the pump gears (see pressure regulation on
page 28). The result is a control of the pump’s delivery rate of fluid to
the hydraulic system.

Figure 25

27

HYDRAULIC CONTROL COMPONENTS
PRESSURE REGULATION
To pressurize pump output there needs to be a restriction in the line
pressure fluid circuit. The main restricting component that controls line
pressure is the pressure regulator valve (208) which is located in the oil
pump assembly (209). Line fluid from the pump is directed to the
middle of the pressure regulator valve and is also orificed to one end of
the valve. The larger surface area at the end of the valve allows the force
from line pressure to move the valve against throttle signal fluid pressure.
EXAMPLE A: MINIMUM LINE PRESSURE (minimum throttle)
As the pump continually supplies fluid and line pressure builds, the
pressure regulator valve moves against the force of the pressure regulator valve spring (207) and throttle signal fluid pressure. This opens the
line pressure circuit at the middle of the valve to enter the ‘converter in’
fluid circuit. Line pressure continues to increase until the pressure regulator valve moves against the spring far enough to open line pressure to
the suction fluid circuit. Excess line pressure at the middle of the valve
then feeds the suction fluid circuit and flows back to the oil pump.
When this occurs, pump output capacity is regulated into minimum line
pressure.

EXAMPLE B: MAXIMUM LINE PRESSURE (maximum throttle)
The pressure regulator valve is constantly regulating pump volume into
the line pressure required to operate the transmission properly. At higher
throttle positions greater line pressure is required to hold the clutches
and the brake band. Therefore, the Transmission Control Module (TCM)
signals the variable force motor (404) to increase throttle signal fluid
pressure (see page 40 for a complete description of force motor operation). Throttle signal fluid pressure assists spring force and moves the
boost valve (205) against the pressure regulator valve. At maximum
throttle, throttle signal fluid pressure moves the pressure regulator valve
enough to block line pressure from entering either the suction or ‘converter in’ fluid circuits. Without a fluid circuit to direct line pressure
into at the pressure regulator valve, line pressure increases to a maximum. Under normal operating conditions, line pressure is regulated
between these minimum and maximum points.
Pressure Regulation in Reverse
Line pressure is boosted in a similar manner during Reverse (R) gear
operation. When Reverse is selected, reverse fluid is routed between the
two lands on the boost valve (205). Because the valve land on the side
closest to the pressure regulator valve is larger, reverse fluid pressure
moves the boost valve against the pressure regulator valve. This assists
spring force and throttle signal fluid pressure, thereby increasing line
pressure.

PUMP
ASSEMBLY
(10)

➤

LINE

➤

➤

LINE

➤

LINE

CONV IN

➤

REVERSE

SUCTION

➤
➤

THROTTLE SIGNAL

➤

LINE
➤

SUCTION

LINE

➤

➤

➤

➤

➤

➤

➤

CONV IN

➤

REVERSE

EX

➤

➤

➤

➤

➤

➤

➤

THROTTLE SIGNAL

➤

➤

EX

➤

➤

LINE

BOOST PRESSURE REGULATOR

➤

➤

➤

➤

➤

➤

BOOST PRESSURE REGULATOR

➤

➤

SUCTION

➤

SUCTION

➤

PUMP
ASSEMBLY
(10)

➤

➤

➤

➤

EXAMPLE "A": MINIMUM

28

LINE

EX
➤ THROTTLE SIG

➤

SUCTION

EX
➤ THROTTLE SIG

LINE

➤

➤

➤

➤

FEED LIMIT

➤

➤

➤

FORCE
MOTOR
SOLENOID
(404)

➤

➤

SUCTION

➤

➤

➤

➤

FORCE
MOTOR
SOLENOID
(404)

➤

FEED LIMIT

EXAMPLE "B": MAXIMUM
Figure 26

HYDRAULIC CONTROL COMPONENTS
COMPONENTS LOCATED IN THE OIL PUMP ASSEMBLY
PRESSURE REGULATOR VALVE TRAIN (203-208)
Pressure Regulator Valve (208)
The pressure regulator valve regulates line pressure according to vehicle
operating conditions. This line pressure is directed into: (a) the ‘converter in’ fluid circuit which is routed to the converter clutch control
valve (210) and, (b) to the pump suction fluid circuit as part of the
pressure regulation (see page 28). Pressure regulation is controlled by
the pressure regulator spring (207), throttle signal fluid pressure and
reverse fluid pressure.
Boost Valve (205)
Acted on by throttle signal fluid pressure from the force motor solenoid
(404), it moves against the pressure regulator valve. This action moves
the pressure regulator valve to increase line pressure. Therefore, as throttle
position increases and the TCM increases throttle signal fluid pressure
at the force motor solenoid, line pressure increases. Also, when Reverse
(R) gear range is selected, reverse fluid pressure moves the boost valve
against the pressure regulator valve to increase line pressure further.

TORQUE CONVERTER CLUTCH (TCC) CONTROL VALVE (210)
TCC Released
The converter clutch control valve (210) is held in the release position
by the converter clutch control valve spring (211) (as shown). This
allows ‘converter in’ fluid to enter the release fluid circuit, flow to the
converter and keep the converter clutch released. Fluid exits the converter in the apply fluid circuit. Apply fluid flows through the converter
clutch control valve and into the cooler fluid circuit.
TCC Apply
To apply the converter clutch, solenoid signal fluid moves the control
valve (210) against spring force. This blocks ‘converter in’ fluid from
entering the release fluid circuit and opens the release fluid circuit to an
exhaust passage. At the same time, line pressure flows through the valve
and feeds the apply fluid passage. Apply fluid is routed to the converter
to apply the converter clutch and fill the converter with fluid.

Throttle Signal Accumulator Assembly (214-217)
Throttle signal fluid pressure acts on the throttle signal accumulator
piston (214) in all gear ranges. This pressure moves the piston against
throttle signal accumulator spring (215) force, thereby dampening any
pressure irregularities occurring in the throttle signal fluid circuit. However, this dampening only affects irregular pulses in the fluid circuit and
not the normal changes in throttle signal fluid pressure as determined by
the TCM at the force motor solenoid (404).

210

211
213

CO

CO
RE NV IN
LE
AS
E
TO
EX
CO
O
AP LER
LIN PLY
E
EX

212

NV

SOLENOID SIGNAL

CL

NT

LINE

214

THROTTLE SIGNAL

➤

215

CO

RO

L

CAPILLARY
RESTRICTION

PUMP
ASSEMBLY
(10)

EX
THROTTLE SIGNAL
ACCUMULATOR
ASSEMBLY
(214-217)

216

LINE

SUCTION

217

203

204

205

206

207

Figure 27

206

SUCTION

LINE

EX

SUCTION

CONVERTER IN

REVERSE

THROTTLE SIGNAL

LINE

BOOST PRESSURE REGULATOR

208

29

HYDRAULIC CONTROL COMPONENTS

COMPONENTS LOCATED IN THE ADAPTER CASE VALVE
BODY

VALVES LOCATED IN THE ADAPTER CASE VALVE BODY
402

Force Motor Solenoid (404)
Controlled by the TCM, it uses a duty cycle operation to regulate feed
limit fluid into throttle signal fluid pressure. Throttle signal fluid pressure is regulated in relation to throttle position and other TCM inputs
that determine vehicle operating conditions (see the Electrical Components Section for additional information). Throttle signal fluid pressure
is routed to the pressure regulator valve to help control line pressure.
Throttle signal fluid pressure is also routed to the 1-2 and 3-4 accumulator control valves (318 and 409) to help regulate accumulator fluid
and control shift feel.

403

409

FORCE
MOTOR
SOLENOID
(404)
FD LIMIT

EX

408

3-4 ACCUM

407

3-4 ACCUM

405

EX

SOME
MODELS

THROTTLE SIGNAL

406

3-4 Accumulator Valve Train (407-409)
This valve train is controlled by throttle signal fluid pressure acting on
the 3-4 accumulator valve (407), spring force, and orificed 3-4 accumulator fluid pressure at the end of the 3-4 accumulator control valve
(409). These forces control the regulation of line pressure into 3-4
accumulator fluid pressure and the exhaust of 3-4 accumulator fluid.
These actions help control the apply feel and release feel of the 4th
clutch.

THROTTLE SIGNAL

THROTTLE SIGNAL

404

406

410

412

LINE

EX

3-4 ACCUM CONTROL

FEED LIMIT

EX

LINE

EX
LINE

EX

FEED LIMIT
411

Note: The 3-4 accumulator control spring is not used on all models.
Refer to page 32A for a detailed description of accumulator control.
Feed Limit Valve (412)
The feed limit valve limits feed limit fluid pressure to a maximum
range of 659 kPa to 765 kPa (96 psi to 111 psi). When line pressure is
below this range the force from the feed limit valve spring (410) keeps
the valve fully open and feed limit fluid pressure equals line pressure.
When line pressure is above this range, orificed feed limit fluid pressure at the end of the valve moves the valve against spring force. This
regulates line pressure entering the feed limit fluid circuit and limits
maximum feed limit fluid pressure to the range given above. Feed limit
fluid is routed to the force motor solenoid.
Torque Converter Clutch (TCC) Solenoid (416)
The TCC solenoid is a normally closed ON/OFF type solenoid that is
controlled by the TCM. When operating conditions are appropriate for
converter clutch apply the TCM energizes the TCC solenoid. This opens
the solenoid and allows solenoid feed fluid to enter the solenoid signal
fluid circuit. To release the converter clutch the solenoid is de-energized, thereby blocking solenoid feed fluid from entering the solenoid
signal fluid circuit. With the solenoid OFF, solenoid signal fluid pressure exhausts through the solenoid and the converter clutch releases.

FEED LIMIT
FORCE MOTOR
SCREEN (415)

2ND CL
REV

406

414

CONVERTER
CLUTCH
SOLENOID
(416)

416

30

402

SOLENOID SIGNAL

413

SOLENOID FEED

EX
415

417

Figure 28

30A

HYDRAULIC CONTROL COMPONENTS
COMPONENTS LOCATED IN THE MAIN CASE VALVE BODY

VALVES LOCATED IN THE MAIN CASE VALVE BODY

1-2/3-4 Shift Valve (304)
The 1-2/3-4 shift valve responds to spring force and D32/1-2 fluid
pressure from the 1-2/3-4 shift solenoid. Also, D32/1-2 fluid pressure at
the spring end of the valve assists spring force in some gear ranges.
Depending on the gear range and the shift solenoid operating state, the
1-2/3-4 shift valve directs or blocks D32/1-2 fluid, servo release fluid,
1-2 regulated fluid and 4th clutch feed 1 fluid. These fluids are routed
into various fluid circuits to apply a clutch or band for the appropriate
gear range - as determined by the TCM or gear selector lever. Also,
some fluids are exhausted through the 1-2/3-4 shift valve to release a
clutch or band during a downshift.

303

Note: Refer to the Power Flow section for a detailed description of the
shift valve operation and electrical component operation in a specific
gear range. Also, refer to the Electrical Component section for a detailed description of each electrical component.

30B

EX

N.C.

EX

1-2 & 3-4 SHIFT

SERVO REL

4TH CL FEED 1
D 3 2/1-2

EX
SERVO REL
D32
EX

EX
4TH CL FD 1

EX
EX

SERVO APPLY
BAND
CONTROL
SOLENOID
PWM
(323)

D 3 2/1-2

EX

1-2 REG

1-2 ACCUM

CONTROL 1-2 ACCUM

2-3 SHIFT

N.O.

D 3 2/1-2

EX

EX

SOLENOID
(307)

EX

D 3 2/1-2

SERVO REL

1-2 ACC

SOLENOID
(303)

323

322

EX

4TH CL FEED 2

321

THROTTLE SIGNAL

1-2 REG
3RD CL FD

305

D 3 2/1-2
D32

D32

1-2 REG

1-2

EX

LOW PRESSURE

1-2

PWM SOLENOID
SCREEN (324)

D32
D32

310

311

312

EX

EX

1-2

P RN D 3 2 1

LINE
R321
1-2

MANUAL VALVE
R321
REVERSE

Pulse Width Modulated (PWM) Band Apply Solenoid (323)
The PWM solenoid is a normally open solenoid that controls the apply
feel of the brake band through a duty cycle operation. The solenoid
regulates D32/1-2 fluid into the servo apply fluid circuit at a duty cycle
determined by the TCM. This regulation controls the rate at which
servo apply fluid pressure increases and the brake band applies. Servo
apply fluid is used to apply the band in First and Second gears.

308

2ND CLUTCH
D 3 2/1-2

307

EX

320

319

310

REV

Manual Valve (326)
The manual valve is supplied line pressure from the pressure regulator
valve and is mechanically linked to the gear selector lever. When a gear
range is selected, the manual valve directs line pressure into various
fluid circuits by opening and closing feed passages. The circuits that are
fed by the manual valve include: Reverse, R321, D32, and 1-2. Remember that the mode switch is connected to the end of the transmissions selector shaft (61) and signals the TCM which gear range the
manual valve is positioned.

309

306

302

2-3 Shift Solenoid Assembly (307)
Controlled by the TCM, this is a normally open shift solenoid that
controls the positioning of the 2-3 shift valve. When energized (ON),
the shift solenoid is closed and blocks D32/1-2 fluid from acting on the
solenoid end of the 2-3 shift valve. When de-energized (OFF), the solenoid opens and D32/1-2 fluid pressure flows through the solenoid, acts
on the end of the shift valve and moves the valve against spring force.

Low Pressure Control Valve (312)
The low pressure control valve reduces 3rd clutch apply pressure in
First gear in Manual First and Manual Second to prevent a harsh 2-1
downshift. Spring force and orificed 1-2 regulated fluid pressure regulate 1-2 fluid into the 1-2 regulated fluid circuit. 1-2 regulated fluid
pressure is approximately 50% that of 3rd clutch fluid pressure experienced in Third and Fourth gears. With 1-2 regulated fluid pressure used
to apply the 3rd clutch in these ranges, this regulation provides a slower
apply of the 3rd clutch than experienced in Third gear.

305

318

2-3 Shift Valve (308)
The 2-3 shift valve responds to D32/1-2 fluid pressure from the 2-3
shift solenoid, spring force, and also D32 fluid pressure in some gear
ranges. Depending on the gear range operation and the shift solenoid
operating state, the 2-3 shift valve directs or blocks D32 fluid and D32/
1-2 fluid. These fluids are routed into the 4th clutch feed 1 and servo
release fluid circuits respectively. 4th clutch feed 1 and servo release
fluids are also exhausted through the 2-3 shift valve during the downshift from Third to Second gear.

Note: The 1-2 accumulator control spring is not used on all models.
Refer to page 32A for a detailed description of accumulator control.

304

SOME
MODELS

1-2/3-4 Shift Solenoid Assembly (303)
Controlled by the TCM, this is a normally closed shift solenoid that
controls the positioning of the 1-2/3-4 shift valve. When de-energized
(OFF) the solenoid is closed and blocks D32/1-2 fluid from acting on
the solenoid end of the 1-2/3-4 shift valve. When energized (turned
ON), the solenoid opens and D32/1-2 fluid pressure flows through the
solenoid, acts on the solenoid end of the shift valve and moves the valve
against spring force.

1-2 Accumulator Valve Train (318-320)
This valve train is controlled by throttle signal fluid pressure acting on
the 1-2 accumulator control valve (318), in addition to spring force and
orificed 1-2 accumulator fluid pressure acting on the end of the 1-2
accumulator valve (320). These forces control the regulation of D32/1-2
fluid into 1-2 accumulator fluid pressure and the exhaust of 1-2 accumulator fluid. These actions help control the apply feel and release feel
of the 2nd clutch.

306

302

324

325

309

326
302

Figure 29

31

clutch. Note that these two clutches must not be applied at the
me.

un Clutch Applied
force keeps the valve normally open, allowing orificed line
e to feed the overrun clutch fluid circuit and apply the overrun
n Park, Reverse, Neutral, First, Second and Third gears. In this
n the valve opens the 4th clutch fluid circuit to an exhaust port,
preventing 4th clutch apply. In Manual First and Manual Sec2 fluid pressure assists spring force to prevent the overrun lockve from shifting into the Fourth gear position under any condi-

gear range is selected and the vehicle is moving forward above approximately 12 km/h (7 mph). Reverse Lockout is not available on all
applications.

apply fluid pressure directed to an accumulator piston opposes a spring
force and an accumulator fluid pressure to create an action similar to a
shock absorber.

Normal Operating Conditions
When the vehicle is stationary and Reverse (R) gear range is selected,
reverse fluid from the manual valve (326) is routed to the end of the
reverse lockout valve. This fluid pressure moves the valve against spring
force, allowing reverse fluid at the middle of the valve to enter the
reverse clutch fluid circuit. Reverse clutch fluid applies the reverse
clutch and Reverse (R) gear range is obtained.

During the apply of a clutch, clutch apply fluid pressure moves the
clutch piston against the clutch piston spring and clutch plates. After
the clearance between the clutch plates is taken up by the clutch piston
travel and the clutch plates begin to hold, fluid pressure in the circuit
builds up rapidly. This clutch apply fluid pressure is also directed to an
accumulator assembly. As the clutch apply fluid pressure increases, it
moves the accumulator piston against spring force and accumulator
fluid pressure. Movement of the accumulator piston delays the pressure
buildup in the circuit and allows for a more gradual apply of the clutch.
Without an accumulator in the clutch apply fluid circuit the rapid buildup
of fluid pressure would cause the clutch to apply very quickly and
possibly create a harsh shift.

Reverse Locked Out
When the vehicle is moving forward above approximately 12 km/h (7
mph) and Reverse (R) gear range is selected, the TCM energizes the
TCC solenoid. With the solenoid ON, solenoid feed fluid flows through
the solenoid and fills the solenoid signal fluid circuit. Solenoid signal
fluid is routed to the spring end of the reverse lockout valve, thereby
assisting spring force to keep the valve closed against reverse fluid
pressure. This blocks reverse fluid from entering the reverse clutch
fluid circuit and prevents the transmission from shifting into Reverse.

utch Applied
in Fourth gear, 4th clutch feed 2 fluid is routed to the end of the
clutch valve. This fluid pressure moves the valve against spring
; (1) block line pressure from entering the overrun clutch fluid
and exhaust overrun clutch fluid, thereby releasing the overrun
and (2) allow 4th clutch feed 2 fluid to fill the 4th clutch fluid
thereby applying the 4th clutch.

SOME
MODELS

702

02

703
703
707

704

705

706

OVERDRIVE LUBE

CK
LO
V

RE
EX

UT

TH CL FD 2

1-2
CL
UT EX
C
LIN H
E
4TH CL FD 2
UN

ER
R
OV

KO

CENTER
SUPPORT
ASSEMBLY
30
(701)

G
SI

LO
C

L

UN

SO

ER
R

E
RS
VE CL
RE EV
R

E

OV

4TH
CL
UT
CH

EX

RS

VE

RE

OU

T

EX

Accumulator Valve Function
The force of the accumulator spring and accumulator fluid pressure
controls the clutch apply rate. At minimum or light throttle, engine
torque is at a minimum and the clutches require less apply force and a
slower apply rate. At heavy throttle, the engine develops a large amount
of torque that requires a greater apply pressure to hold the clutches and
a faster apply rate to prevent the clutch plates from slipping during
apply. To compensate for these various operating conditions, an accumulator valve regulates accumulator fluid pressure proportional to
throttle position and engine torque.
At greater throttle positions, throttle signal fluid pressure increases and
the accumulator valve regulates accumulator fluid to a higher pressure.
The increase in accumulator fluid pressure decreases the distance that
clutch apply fluid pressure can move the accumulator piston. This decreases the accumulators cushioning effect and allows clutch apply
fluid pressure to increase more rapidly for a faster clutch apply. Remember that throttle signal fluid pressure acting on the accumulator
valves is regulated relative to throttle position and engine torque. Remember that the TCM controls throttle signal fluid pressure through
the force motor solenoid.
1-2 ACCUMULATOR ASSEMBLY (313-316)
The 1-2 accumulator assembly is located in the main case valve body
(84) and consists of a piston (315), piston spring (316) and piston pin
(313). The 1-2 accumulator assembly is the primary device for controlling the apply feel of the 2nd clutch during a 1-2 upshift.
Upshift Control
During a 1-2 upshift (as shown in Figure 31), 2nd clutch fluid is routed
to both the 1-2 accumulator assembly and the 2nd clutch. The rapid
buildup of fluid pressure in the 2nd clutch fluid circuit strokes the
accumulator piston (315) against 1-2 accumulator fluid pressure and
the force from the 1-2 accumulator spring (316). This action absorbs
some of the initial 2nd clutch fluid pressure and provides a time delay
to cushion the 2nd clutch apply.
As 2nd clutch fluid pressure moves the 1-2 accumulator piston some
1-2 accumulator fluid is forced out of the 1-2 accumulator. This fluid is
routed back to the 1-2 accumulator valve train. The orificed 1-2 accumulator fluid pressure acting on the end of the 1-2 accumulator valve
(320) moves the valve train against spring force and throttle signal
fluid pressure. This blocks D32/1-2 fluid and regulates the excess 1-2
accumulator fluid past the 1-2 accumulator valve and through an exhaust port. This regulation provides additional control for the accumulation of 2nd clutch fluid pressure and the 2nd clutch apply rate.

HYDRAULIC CONTROL COMPONENTS
ACCUMULATOR ASSEMBLIES

➤

Downshift Control
During a 2-1 downshift, 2nd clutch fluid exhausts from the 1-2 accumulator assembly. As spring force and 1-2 accumulator fluid pressure
move the 1-2 accumulator piston against exhausting 2nd clutch fluid,
the 1-2 accumulator valve train regulates more D32/1-2 fluid into the
1-2 accumulator fluid circuit. This regulation controls the rate at which
1-2 accumulator fluid fills the 1-2 accumulator. It also helps control the
rate at which 2nd clutch fluid exhausts and the 2nd clutch releases.
Therefore, with higher throttle positions and greater throttle signal fluid
pressure, the accumulator valve will regulate D32/1-2 fluid to fill the 12 accumulator faster. This pressure will then move the accumulator
piston faster, thereby forcing 2nd clutch fluid to exhaust faster and the
2nd clutch to release quicker.

➤

CAPILLARY
RESTRICTION

➤

THROTTLE SIGNAL

➤

EX

THROTTLE SIGNAL ACCUMULATOR ASSEMBLY (214-217)
4TH CLUTCH
➤

13

The 3-4 accumulator assembly functions exactly the same as the 1-2
accumulator assembly. The only difference is the name of the fluids
used. In the 3-4 accumulator, line pressure feeds the 3-4 accumulator
fluid circuit through the 3-4 accumulator valve and 4th clutch fluid
strokes the accumulator piston during the 4th clutch apply.

➤
➤
EX

➤

EX

➤

➤

THROTTLE SIGNAL
16

3-4 ACCUM CONTROL

17

18

EX

2ND CLUTCH

➤

3-4 ACCUMULATOR ASSEMBLY (13-19)

103

313

➤

315

101

➤

➤

1-2 ACCUM

➤

THROTTLE SIGNAL

102

SERVO APPLY
SERVO RELEASE

➤

➤

➤

314

100

99

➤

98

316

➤

D 3 2/1-2

➤

97

➤

➤

96
95

EX

➤

EX

CONTROL 1-2 ACCUM
➤

94

1-2 ACCUMULATOR ASSEMBLY

32B

19

➤

➤

LINE

As the servo piston moves to the release position, some servo apply
fluid is forced out of the servo assembly. This fluid is routed back
through the Pulse Width Modulated (PWM) band apply solenoid (323)
and into the D32/1-2 fluid circuit. This excess fluid pressure is regulated back through the pressure regulator valve.

THROTTLE SIGNAL ACCUMULATOR ASSEMBLY (214-217)
This accumulator dampens the pressure irregularities in he throttle signal fluid circuit. Refer to page 29 for “Components Located in the Oil
Pump Assembly” for a description.

15

3-4 ACCUM

Upshift Control
The 3rd clutch is applied by 3rd clutch fluid pressure which is fed by
servo release fluid. Servo release fluid is also routed to the servo assembly and acts on the release side of the servo piston. Servo release
fluid pressure assists the force from the servo cushion and servo return
springs to move the servo piston against servo apply fluid pressure.
This action moves the servo piston (97) and apply rod (102) away from
the brake band, thereby releasing the band. The movement of the servo
piston absorbs some of the initial 3rd clutch fluid pressure to cushion
the 3rd clutch apply - similar to the accumulation action of the 1-2 and
3-4 accumulators.

Note: Refer to the Electronic Components Section for a detailed description of the PWM solenoid operation.

14

➤

Note: The accumulator control springs (319 and 408) for the 1-2 and
3-4 accumulator valve trains are not used on all models. Refer to the
appropriate service information for specific application information.

Downshift Control
During a 3-2 downshift, servo release fluid exhausts from the servo
assembly. As the force from the servo cushion spring (99), servo return
spring (103), and servo apply fluid pressure move the servo piston to
the apply position, the PWM solenoid regulates more D32/1-2 fluid
into the servo apply fluid circuit. This regulation controls the rate at
which servo apply fluid pressure fills the servo assembly and moves
the servo piston to apply the brake band. This action also helps control
the rate at which servo release fluid exhausts and the 3rd clutch releases. The PWM solenoid is controlled by the TCM in relation to the
operating conditions of the vehicle.

217

216

➤

3-4 ACCUMULATOR ASSEMBLY (13-19)
The 3-4 accumulator assembly is located in the side of the adapter case
(20) and consists of a piston (18), piston spring (16) and piston pin
(17). The 3-4 accumulator assembly is the primary device for the controlling the apply feel of the 4th clutch during a 3-4 upshift.

3RD CLUTCH ACCUMULATION
The servo assembly (90-103) is used as an accumulator during the 2-3
upshift to cushion the 3rd clutch apply. The servo assembly is located
in the bottom rear of the main transmission case (36) and consists of a
piston (97), a cushion spring (99), a return spring (103) and an apply
rod (102).

215

214

SERVO ASSEMBLY (94-103)
Figure 31

33

HYDRAULIC CONTROL COMPONENTS
CHECKBALL LOCATION AND FUNCTION
REVERSE
SHUTTLE
(85)
➤ 20f

➤

21

14l

SOLENOID FEED

➤

2ND CL
REVERSE

D32
SHUTTLE
(85)

1-2

REVERSE
SHUTTLE
VALVE
(85)
D32

29f

16d

➤

➤

ADAPTER CASE (20)
(AUX. VALVE BODY SIDE)

QUICK
DUMP
VALVE
(85)

17

D32
SHUTTLE
VALVE
(85)

➤

MAIN CASE (36)
(TO VALVE BODY)

D 3 2/1-2

34

Figure 32

22d

SERVO REL

SERVO RELEASE

3RD CLUTCH
QUICK DUMP
VALVE (85)

23c

3RD CL FEED

24

SERVO REL ➤ 22/23a

23b
➤

3RD CL

➤

CONVERTER CLUTCH APPLY CHECKBALL
Located in release fluid circuit at the end of the turbine shaft (506), it controls the
apply feel of the torque converter clutch (TCC). As the TCC applies, exhausting
release fluid seats, and is orificed around, the checkball. The orifice slows the
exhaust of release fluid and controls the apply feel of the converter clutch. When
the TCC is released, release fluid pressure unseats the checkball and flows freely
past the ball to keep the pressure plate away from the converter cover.

22e

➤

REVERSE SHUTTLE VALVE (SOME APPLICATIONS ONLY)
Located in the adapter case (20), it controls the routing of fluid into the solenoid
feed fluid circuit. Depending on the position of the manual valve and the gear
range the transmission is operating in, either reverse fluid or 2nd clutch fluid
feeds the solenoid feed fluid circuit. If one of these fluids is present it seats the
checkball against the other fluid circuit, which would be empty, and fills the
solenoid feed fluid circuit in preparation for converter clutch apply (reverse fluid
and 2nd clutch fluid are never present at the same time). Remember that converter
clutch apply in Reverse (R) is only during a ‘Reverse Lock Out’ condition.

➤

➤

3RD CLUTCH CHECK VALVE
Located in the main case valve body (84), it controls the routing of fluid into the
3rd clutch fluid circuit. Depending on the gear range the transmission is operating
in, either servo release fluid, 3rd clutch feed fluid or both fluids feed the 3rd
clutch fluid circuit. When only one of these fluids is present the checkball seats
against the empty fluid circuit. If servo release and 3rd clutch feed fluids are both
present, the checkball remains in a released state as these fluids feed the 3rd
clutch fluid circuit.
3RD CLUTCH QUICK DUMP VALVE
Located in the main transmission case (36), it controls the exhaust rate of servo
release fluid. When the transmission downshifts from Third to Second gear, servo
release fluid pressure exhausts. Exhausting servo release fluid pressure seats the
checkball and is forced through the orifice next to the checkball. Forcing exhausting servo release fluid through the orifice helps controls the release rate of the 3rd
clutch and the apply of the brake band. To apply the 3rd clutch, servo release fluid
unseats, and flows past the #3 checkball, thereby bypassing the orifice opposite
the checkball.

➤

D32 SHUTTLE VALVE
Located in the main transmission case (36), it controls the routing of fluid into the
D32/1-2 fluid circuit. Depending on the position of the manual valve, either D32
fluid, 1-2 fluid or both fluids feed the D32/1-2 fluid circuit. When only one of
these fluids is present the checkball seats against the empty fluid circuit. If D32
and 1-2 fluids are both present, the checkball remains in a released state as both
of these fluids feed the D32/1-2 fluid circuit.

➤

3RD CLUTCH
CHECK VALVE
(85)

3RD CLUTCH
CHECK VALVE
(85)

VALVE BODY (84)
(MAIN CASE)

ELECTRICAL COMPONENTS
The Hydra-matic 4L30-E transmission incorporates electronic controls that
utilize a Transmission Control Module (TCM). The TCM gathers vehicle
operating information from the various sensors and controls listed below,
sensors both internal and external to the transmission. The TCM processes
this information and controls the following:
•
•
•
•

‘fail-safe mode’. In fail-safe mode, the following defaults occur:
• The Force Motor solenoid is OFF and line pressure is a maximum to
prevent any clutch slippage.
• The PWM Band Apply solenoid is OFF and servo apply fluid pressure is
a maximum to prevent the band from slipping.
• The TCC solenoid is OFF and converter clutch apply is prevented.
• Both shift solenoids are OFF.

transmission shift points through the shift solenoids,
transmission shift feel through the force motor solenoid,
TCC apply and release timing through the TCC control solenoid, and
the brake band apply rate through the PWM band apply solenoid.

With both shift solenoids OFF (Fourth gear state), the transmission will
operate in Fourth gear when the gear selector lever is in the Drive range
position. However, the driver has some flexibility in gear selection during
fail-safe mode by moving the gear selector lever as follows: (see note)

Electronic control of these transmission operating characteristics provides
consistent and precise shift points and shift quality based on the operating
conditions of both the engine and transmission.

Gear Selector Lever Position Transmission Gear Operation
Drive Range (D)
Manual Third (3)
Manual Second (2)
Manual First (1)
Reverse (R)
Park, Neutral (P,N)

OPERATING MODES
The TCM controls the transmission operation in three modes: Economy
mode, Performance mode, and Winter mode. The driver determines the
transmission operating mode through the Performance/Economy mode
switch and Winter mode switch. Some applications have a Manual mode
where the transmission can be shifted manually, similar to a manual transmission. Refer to page 40 for more information on these different operating modes.

Note: When the system failure is not due to the TCM, and the TCM is
functioning properly, the transmission will operate in Second gear when
the selector lever is in the Manual First position. In this situation the TCM
operates the shift solenoids in a Second gear state. Some applications
have different fail-safe operating states. Refer to the appropriate service
manual for specific information.

FAIL-SAFE MODE
If a major electrical system failure occurs which could affect vehicle safety
or damage the transmission during normal operation, the TCM enters the

D

4th gear
4th gear
3rd gear
1st gear
Reverse
Park, Neutral

D1C

TCM

J

K

"CHECK TRANS"
LAMP

➤

➤

➤
➤

➤

E

➤

➤

➤

➤

➤

➤

➤
➤

➤
➤

➤

➤

➤
➤

➤

➤
➤

➤

I

G

2

5

3 4

C

INPUTS

1

A

ETCM

H

F

OUTPUTS

INFORMATION SENSORS

ELECTRONIC CONTROLLERS

A. TRANSMISSION OUTPUT SPEED SENSOR
B. TRANSMISSION FLUID TEMPERATURE
SENSOR
C. MODE SWITCH
D. THROTTLE POSITION SENSOR (TPS)
E. ENGINE SPEED SENSOR
F. BRAKE SWITCH
G. ENGINE COOLANT TEMPERATURE SENSOR
H. KICKDOWN SWITCH
I. AIR CONDITIONER INFORMATION SIGNAL
J. WINTER MODE PUSHBUTTON SWITCH
K. ECONOMY/PERFORMANCE PUSHBUTTON
SWITCH

•
•
•

➭

ELECTRONICALLY CONTROLLED
TRANSMISSION COMPONENTS

TRANSMISSION CONTROL MODULE (TCM)
DIAGNOSTIC 1 CONNECTOR (D1C)

1. PULSE WIDTH MODULATED (PWM)
BAND APPLY SOLENOID

SELF DIAGNOSTIC INPUT ("CHECK TRANS"
LAMP)

2. FORCE MOTOR SOLENOID

➭

3. 1-2/3-4 SHIFT SOLENOID
4. 2-3 SHIFT SOLENOID
5. TORQUE CONVERTER CLUTCH
SOLENOID

Figure 33

35

ELECTRICAL COMPONENTS
ELECTRICAL COMPONENTS (TCM inputs internal to the
transmission)

ELECTRICAL
CONNECTOR

TRANSMISSION OUTPUT SPEED SENSOR (39)
The transmission output speed sensor is a magnetic inductive pickup
that relays information relative to vehicle speed to the TCM. The
speed sensor is mounted in the side of the transmission extension
assembly (37), opposite of the parking lock wheel (668). The parking
lock wheel is splined to the output shaft and has teeth on its outside
diameter. Therefore, the parking lock wheel rotates at transmission
output speed.

O-RING
ROTOR

The speed sensor assembly consists of a permanent magnet surrounded
by a coil of wire. As the output shaft and parking lock wheel rotate,
an alternating current (AC) is induced in the coil of wire by the teeth
on the parking lock wheel passing by the magnetic pickup. Therefore,
whenever the vehicle is moving, the output speed sensor produces an
AC voltage signal proportional to vehicle speed. As vehicle speed
increases and more teeth pass by the magnetic pickup on the speed
sensor in a given time frame, the frequency of the AC signal increases. An increase in frequency of the AC signal is interpreted by
the TCM as an increase in vehicle speed (see Figure A).

MAGNETIC
PICKUP

OUTPUT VOLTS

SPEED SENSOR

5.0

HIGH SPEED

LOW SPEED

TIME

➤

FIGURE A: CONDITIONED SIGNAL

The TCM inhibits TCC apply until transmission fluid temperature
reaches approximately 30˚C (86˚F). F or some applications if transmission fluid temperature becomes excessively high, above approximately 140°C (284°F), the TCM will apply the converter clutch in
Second, Third and Fourth gears regardless of operating conditions.
Normally the TCC is only applied in Third and Fourth gears. Applying
the TCC serves to reduce transmission fluid temperatures created by
the fluid coupling in the torque converter when the TCC is released.

WIRE

16,000

133
-10

110

TEMPERATURE (°C)

3

MODE SWITCH
The mode switch signals the TCM which position the selector lever is
in and the gear range the transmission is operating in. The mode
switch is bolted to the outside of the main transmission case (36) and
splined to the transmission selector shaft (61). Therefore, the digital
logic in the mode switch determines which position the selector shaft
is in and this information is then sent to the TCM.

WIRE

RESISTOR

TEMPERATURE SENSOR
NORMAL RESISTANCE (OHMS)

TRANSMISSION FLUID TEMPERATURE SENSOR
This sensor is a negative temperature coefficient thermistor (temperature sensitive resistor) that is bolted on the adapter case valve body
assembly (401). The temperature sensor is submersed in the fluid in
the adapter case bottom pan (50). The internal electrical resistance of
the sensor varies according to the operating temperature of the transmission fluid (see chart). The lower the fluid temperature, the higher
the resistance. The TCM interprets this resistance as another input to
help control the converter clutch application through the TCC control
solenoid. This information is also used to control line pressure through
the force motor solenoid.

D

N

R
P

2
1

G
C
B
A

Note: For the mode switch to function properly, it is important to
correctly align the mode switch with the selector shaft each time the
switch is removed and reassembled. Refer to the appropriate service
information for the specific procedure to assemble the mode switch.

MODE SWITCH

36

Figure 34

ELECTRICAL COMPONENTS
ELECTRICAL COMPONENTS (TCM inputs/outputs external to the transmission)
THROTTLE POSITION SENSOR (TPS)
Located on the throttle shaft of the TBI unit, the TCM monitors a variable voltage signal from this sensor to calculate throttle position. The
TPS is a potentiometer that varies from approximately .48 volts at minimum throttle position to approximately 4.5 volts at maximum throttle
position. The TCM measures this voltage and uses the information on
throttle position to determine the appropriate shift patterns, shift feel and
TCC apply and release timing. In general, with greater throttle angle and
higher TPS voltage signal, the TCM delays upshift speeds (through shift
solenoid control) and increases line pressure (through force motor solenoid control). Also, the TCM keeps the converter clutch released at
minimum throttle positions and during heavy acceleration.
ENGINE SPEED SENSOR
Monitored as engine RPM by the TCM through the ignition module, this
sensor is used to help determine shift patterns and TCC apply and release timing.
ENGINE COOLANT TEMPERATURE SENSOR
This sensor monitors engine coolant temperature and sends a variable
resistance signal to the Engine Control Module (ECM). When the engine
is cold, resistance through the sensor is high, and when the engine is hot,
resistance is low. The ECM then sends this information to the TCM. The
TCM prevents converter clutch apply when engine coolant temperature
is below approximately 70˚C (158˚F).
BRAKE SWITCH
This switch causes the TCM to command TCC release. When the brake
pedal is depressed the TCM opens the path to ground for the TCC
solenoid electrical circuit. This de-energizes the solenoid and releases
the converter clutch.
KICKDOWN SWITCH
This switch is connected to the accelerator pedal. Whereas the TPS
signals throttle position to the TCM, the kickdown switch signals the
TCM when the accelerator pedal is fully depressed. The kickdown switch
is activated when the accelerator pedal travel is approximately 80%.
AIR CONDITIONER INFORMATION SIGNAL
When the A/C pressure cycling switch closes, the TCM is signaled that
the air conditioning compressor is ON and there is an extra load on the
engine. The TCM then adjusts transmission line pressure and shift timing to compensate for the added load on the engine.
ECONOMY/PERFORMANCE MODE PUSHBUTTON SWITCH
Depressing this pushbutton changes the transmission operating mode
between the Economy and Performance driving modes. In Performance
mode, the TCM delays part-throttle upshifts for greater acceleration. The
TCM also signals the force motor solenoid to increase line pressure for
the additional torque requirements in Performance mode. Higher line
pressure creates firmer shifts and more holding force for the friction

TORQUE CONVERTER CLUTCH SOLENOID (416)
The converter clutch solenoid is an ON/OFF solenoid connected to the
adapter case valve body. The solenoid is normally closed and functions
identical to the 1-2/3-4 shift solenoid. When de-energized (OFF), solenoid
spring force keeps the plunger against the fluid inlet port. This blocks
solenoid feed fluid pressure from entering the solenoid signal fluid circuit.
With the plunger in this position the solenoid signal fluid circuit is open
to an exhaust port through the end of the solenoid. Without solenoid
signal fluid pressure the TCC is kept released.

clutches and the brake band. Economy mode provides better fuel economy
by having the TCM initiate earlier part-throttle upshifts. Also, in Economy
mode line pressure is lower to provide smoother upshifts and downshifts.
WINTER MODE PUSHBUTTON SWITCH
In Winter mode the TCM changes the shift solenoid states to start the
transmission in Third gear. By starting to move the vehicle with the
transmission in Third gear, less torque is created, thereby reducing tire
slippage on ice and snow. When the driver selects Winter mode the TCM
overrides the selection of Economy or Performance modes. The TCM
only enters Winter mode when the following conditions are met:
•
•
•
•

The selector lever is in the Drive Range (D).
Vehicle speed is less than 10 km/h (6 mph).
Transmission fluid temperature is less than 130˚C (266˚F).
The kickdown switch is off and throttle opening is less than 7%.

Winter mode is cancelled if any of the following conditions are met:
• The Winter mode button is depressed.
• The selector lever is moved from the Drive Range (D) position (the
TCM will remain in Winter mode in Neutral and Reverse).
• The ignition key is turned off.
• Vehicle speed is greater than 30 km/h (19 mph) for more than one.
• Transmission fluid temperature is greater than 130˚C (266˚F).
• Kickdown switch is activated.
When Winter mode is cancelled by one of these conditions, the TCM
returns to operating in Economy mode, regardless of the operating mode
before selecting Winter mode.
MANUAL MODE (SOME MODELS ONLY)
Some 4L30-E applications can be operated in a Manual mode. When
Manual mode is selected the transmission gear state follows the position
of the gear selector lever as follows:
Gear Selector Lever Position Transmission Gear Operation
Drive Range (D)
Manual Third (3)
Manual Second (2)
Manual First (1)

4th gear
3rd gear
2nd gear
1st gear

This allows the driver to operate the transmission similar to a manually
shifted transmission.

• Transmission fluid must be above approximately 30˚C (86˚F) bef ore
the TCM will signal TCC apply.
• Engine coolant temperature must be above approximately 70˚C (158˚F)
before the TCM will signal TCC apply.
• In the event of an electrical or system failure the TCC solenoid remains
OFF and the TCC released.

When energized (turned ON) by the TCM, the magnetic field created in
the coil moves the plunger against solenoid spring force, away from the
fluid inlet port, and blocks the exhaust port through the solenoid. This
allows solenoid feed fluid to flow through the solenoid and fill the solenoid
signal fluid circuit. With the exhaust port blocked, solenoid signal fluid
pressure increases, thereby moving the TCC control valve into the apply
position and initiating the TCC apply.

CONNECTOR

SPRING

O-RING

EXHAUST

The TCC is normally applied in Third and Fourth gears (but will apply
in Second gear on some models if transmission fluid temperatures become
excessively high). The following conditions will cause the TCM to change
the operating state of the solenoid:
• The TCC is released prior to all upshifts and downshifts and may reapply after the shift is complete if operating conditions are appropriate.
• The TCC is released when the brake pedal is depressed, as signaled to
the TCM by the brake switch.

Figure 35

COIL
ASSEMBLY

PLUNGER

SOLENOID SOLENOID
FEED
SIGNAL
FLUID
FRAME FLUID

37

ELECTRICAL COMPONENTS
CONNECTOR

SPRING

O-RING

SHIFT SOLENOIDS
The Hydra-matic 4L30-E transmission uses two electronic shift solenoids (the 1-2/3-4 and 2-3 shift solenoids) to control upshifts and downshifts in all forward gear ranges. These shift solenoids work together in
a combination of ON and OFF sequences to control the positions of the
1-2/3-4 and 2-3 shift valves. The TCM uses numerous inputs to determine which solenoid state combination, and which gear range, the
transmission should be in. The following table indicates the solenoid
state combination required for each gear range:

EXHAUST

GEAR RANGE

COIL
ASSEMBLY

PLUNGER

OFF

ON

First

OFF

ON

Second

ON*

ON

Third

ON*

OFF*

Fourth

OFF

OFF*

1-2 & 3-4 SHIFT SOLENOID (NORMALLY CLOSED)
CONNECTOR

SPRING

METERING O-RING
BALL

COIL
ASSEMBLY

D32/1-2
FLUID

FRAME

PLUNGER

2-3 SHIFT SOLENOID (NORMALLY OPEN)

SOLENOID
(303)

EX

EX
➤

EX

SERVO REL
D32 ➤

EX

EX

2-3 SHIFT

N.O.
ON

4TH CL FD 1

SOLENOID
(307)

SERVO REL
4TH CL FD 1
➤

D 3 2/1-2
D 3 2/1-2

2ND CLUTCH
D 3 2/1-2

1-2 & 3-4 SHIFT
➤

N.C.
OFF

➤

3RD CL FEED
1-2 REG
4TH CL FEED 2

EX

EXAMPLE A: FIRST GEAR

➤

➤

EX

EX

1-2 & 3-4 SHIFT
➤

➤

➤

When energized (turned ON) by the TCM, the magnetic field created
in the coil moves the plunger against solenoid spring force, away from
the fluid inlet port, and blocks the exhaust port through the solenoid.
This allows D32/1-2 fluid to flow through the solenoid and act on the
1-2/3-4 shift valve. With the exhaust port blocked, D32/1-2 fluid pressure at the end of the shift valve increases, moves the valve against
spring force and into the Second and Third gear positions (as shown in
Example B).
2-3 Shift Solenoid (307)
Located at the end of the 2-3 shift valve (308), the 2-3 shift solenoid is
normally open and fed D32/1-2 fluid. When de-energized (OFF), D32/
1-2 fluid pressure moves the solenoid checkball against solenoid spring
force. This also moves the plunger in the solenoid to block the exhaust
port in the solenoid. D32/1-2 fluid flows past the ball and acts on the 23 shift valve. With the exhaust port blocked, D32/1-2 fluid pressure at
the end of the shift valve increases. D32/1-2 fluid pressure moves the
shift valve against 2-3 shift valve spring (305) force and into the Third
and Fourth gear position (as shown in Example B).
When energized (ON - Example A) by the TCM, the magenetic field
created in the coil moves the plunger against the solenoid checkball.
The force from the plunger assists spring force and seats the ball against
the fluid inlet port, thereby blocking D32/1-2 fluid. With the plunger in
this position, residual D32/1-2 fluid at the end of the shift valve is open
to the exhaust passage through the solenoid. This allows shift valve
spring force to move the 2-3 shift valve into the First and Second gear
position.

➤
➤

➤

EX

2-3 SHIFT
EX

N.O.
OFF

➤

EX

SOLENOID
(307)

SERVO REL

4TH CL FD 1
➤

D 3 2/1-2
D 3 2/1-2

1-2/3-4 Shift Solenoid (303)
Located at the end of the 1-2/3-4 shift valve (304), the 1-2/3-4 shift
solenoid is normally closed and fed D32/1-2 fluid. When de-energized
(OFF), solenoid spring force keeps the plunger against the fluid inlet
port. This blocks D32/1-2 fluid pressure from acting on the 1-2/3-4
shift valve. Without D32/1-2 fluid pressure, 1-2/3-4 shift valve spring
(305) force keeps the shift valve in the First and Fourth gear position
(as shown in Example A). With the shift valve in this position the
cavity at the end of the valve is open to an exhaust port through the
solenoid.

EX

N.C.
ON

2ND CL
D 3 2/1-2

➤

SOLENOID
(303)

➤

3RD CL FEED
1-2 REG
4TH CL FEED 2
EX

* Denotes the solenoid is open with fluid pressure flowing
through the shift solenoid and acting on the shift valve.

The shift solenoids are de-energized (turned OFF) when the TCM opens
the path to ground for the solenoid’s electrical circuit. When the TCM
provides a path to ground for the electrical circuit, the solenoid is
energized (turned ON), current flows through the coil assembly in the
solenoid and creates a magnetic field. This magnetic field moves the
plunger inside the solenoid to change the operating state of the solenoid.

EXHAUST

EX

SERVO REL
D32

4TH CL FD 1
EXAMPLE B: THIRD GEAR

38

2-3 Solenoid
Normally Open

Park, Reverse, Neutral
D32/1-2
FLUID

FRAME

1-2/3-4 Solenoid
Normally Closed

Figure 36

ELECTRICAL COMPONENTS
PULSE WIDTH MODULATED (PWM) BAND APPLY SOLENOID (323)

VOLTS

TIME
➤

➤

VOLTS

1 CYCLE = 1/32 SECOND

16
14
12
10
8
6
4
2
0

FREQUENCY: 32 HZ

TIME
➤

1 SECOND
(32 CYCLES)
DUTY CYCLE = 70%

➤

FIGURE A: PWM SOLENOID NEGATIVE DUTY CYCLE
HOUSING

O-RING

CENTER
POLE
FLOW
REGULATION
(EXHAUST)

METERING
BALL

SNAP
RING

➤ ➤

➤

➤

➤

➤

➤

COIL
ASSEMBLY
EXHAUST
SEAT

SPOOL
HOUSING

➤

➤

PRESSURE PRESSURE
CONTROL
SUPPLY
(D32/1-2) (SERVO APPLY)

CONNECTOR

SPRING

Figure 37

BAND
APPLY

100%
80

A

➤

Brake Band Release
The solenoid state during the band release depends on vehicle speed
and gear selector lever position. During a shift from a forward Drive
Range to Park, Reverse, or Neutral, or a 2-3 upshift at speeds above
approximately 20 km/h (13 mph), the TCM operates the solenoid at a
0% duty cycle (solenoid valve to the right - fully open). This allows
excess servo apply fluid pressure to exhaust quickly through the solenoid, thereby releasing the band quickly.

➤

PULSE WIDTH MODULATED (PWM) BAND APPLY SOLENOID

PERCENT DUTY CYCLE

Figure B shows an example of the relation between Percent Duty Cycle
and Time that controls the brake band apply rate. The TCM immediately increases the solenoid duty cycle to between 0% and 80% (point
A). Once the band applies, the duty cycle immediately decreases to 0%
and the solenoid is de-energized (turned OFF) to achieve maximum
servo apply fluid pressure (point B). The value of the duty cycle controls the brake band apply rate and apply feel as determined by vehicle
application and operating conditions.

➤

(ON)

➤

Without D32/1-2 fluid pressure at the end of the valve, the fluid dynamics acting on the valve shifts it completely to the left (with respect
to the drawing). This blocks D32/1-2 fluid from entering the valve and
supplying the servo apply fluid circuit. A higher percent duty cycle
increases the current flowing through the solenoid, thereby increasing
the coil's magnetic field. This keeps the checkball further toward the
exhaust seat, and the valve further to the left, to provide a slower
increase in servo apply fluid pressure and slower apply of the brake
band.

70%

➤

0

➤

Brake Band Application Rate
If the solenoid remained OFF and fully open (0% duty cycle) during
the band apply, servo apply fluid pressure would increase too rapidly
and create a harsh shift. Therefore, to control the band apply rate, the
solenoid’s duty cycle is increased from 0%. The TCM sends an electrical current through the solenoid coil at the same rate as the duty cycle
which creates a magnetic field that magnetizes the center pole (grey
cross hatch area). The magnetized pole repels the ball against spring
force, seating the ball against the inlet port. This allows D32/1-2 fluid
from the end of the valve to exhaust past the ball and through the
solenoid.

30%

12

➤

Brake Band Applied
When the band is applied, the electrical path to ground for the solenoid
is always open and the negative duty cycle is 0%. Therefore, current
does not flow through the coil in the solenoid and the PWM solenoid is
always OFF (as shown in the drawing). With the solenoid OFF, solenoid spring force holds the ball away from the D32/1-2 fluid inlet port
and against the exhaust seat in the solenoid. This allows D32/1-2 fluid
to flow through the inlet port, past the ball, and into the two passages
leading to the solenoid valve. This D32/1-2 fluid pressure moves the
valve completely to the right (with respect to the drawing). With the
valve in this position, D32/1-2 fluid flows through the valve and enters
the servo apply fluid circuit.

Note: The duty cycle percentages in Figure B are only approximate
values and do vary with vehicle application and vehicle operating
conditions.

➤

The PWM solenoid operates on a negative duty cycle. This means that
the ground (negative or low) side of the solenoid circuit is controlled
by the TCM. The solenoid is constantly fed approximately 12 volts to
the high (positive) side and the TCM controls the length of time the
path to ground for the electrical circuit is closed (duty cycle). When the
TCM closes the solenoid ground circuit, current flows through the
solenoid and the ground circuit is at a low voltage state (0 volts and
solenoid energized).

Approximately every 15 seconds the TCM pulses the band apply solenoid to either a maximum or minimum duty cycle. These pulses function to prevent possible contamination from sticking the solenoid valve
or plunger in any given position.

➤

Figure A shows an example of the PWM solenoid operating with a
70% negative duty cycle at the constant operating frequency of 32 Hz
(cycles per second). The frequency means that when the solenoid is
energized it is pulsed with current from the TCM 32 times each second. The 70% duty cycle means that during each cycle (1/32 of a
second) the solenoid is energized (ON) and closed 70% of the time
(see inset in Figure A). With the solenoid being normally open, a
greater duty cycle equates to the solenoid being closed more often and
less fluid flowing through the solenoid (closed with respect to D32/1-2
fluid entering the valve and servo apply fluid circuit).

During a 2-3 upshift at low speed, below approximately 20 km/h (13
mph), the TCM operates the solenoid at 100% duty cycle. With a 100%
duty cycle the solenoid valve is positioned completely to the left, with
respect to the cutaway view of the solenoid, and blocks exhausting
servo apply fluid from entering the valve and the D32/1-2 fluid circuit.
This forces the exhausting servo apply fluid pressure through orifice
#17/19e. orificing this fluid slows the exhaust and creates a slower
band release. At low speeds a slow band release is needed to prevent a
harsh release feel.

➤

General Operation
The PWM solenoid is a normally open solenoid that controls the brake
band apply and release. This is accomplished by the TCM varying the
solenoid’s duty cycle (percent time energized) in relation to vehicle
operating conditions and the various TCM input signals. The brake
band is always applied in First and Second gears.

60
40
20
0

B

TIME
➤

FIGURE B: BRAKE BAND APPLY

39

ELECTRICAL COMPONENTS
FORCE MOTOR (404)
The variable force motor solenoid, controlled by the TCM, is a precision electronic pressure regulator that controls line pressure. The force
motor operates at approximately 600 Hz (cycles per second) and regulates feed limit fluid pressure into the throttle signal fluid circuit. The
TCM controls the pressure that throttle signal fluid is regulated at by
varying the current at the force motor coil. The amount of current is
controlled by the duty cycle of the force motor. A greater duty cycle
creates a higher current at the force motor. Similar to the PWM solenoid, the duty cycle represents the percent time that current flow
energizes the coil. The high frequency of the force motor acts to
smooth the pulses created by the duty cycle energizing and de-energizing the force motor.

➤ ➤

DAMPER
SPRING

COIL
ASSEMBLY

PLUNGER

➤ ➤

➤

60%➤
(ON)

VOLTS

12

40%

➤

TIME

0

➤
➤

➤

1 CYCLE = 1/292.5 SECOND

FIGURE B: FORCE MOTOR POSITIVE DUTY CYCLE

NOMINAL FLUID PRESSURE (PSI)

FORCE MOTOR LINE PRESSURE CONTROL
240
210
LINE (DRIVE)

180
150
120
90

THROTTLE SIGNAL (NOM)

60
30
0
0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

INPUT CURRENT (AMP)

40

FRAME

FIGURE A: FORCE MOTOR (OFF)

Under normal operating conditions between maximum and minimum
throttle positions, the TCM varies the duty cycle which varies current
flow to the force motor between approximately 0.1 and 1.1 amps to
control throttle signal fluid pressure. This regulates the valve between
opening and closing the exhaust port to regulate throttle signal fluid
pressure. Throttle signal fluid pressure then controls line pressure at
the pressure regulator valve accordingly (see chart). If the electrical
system becomes disabled for any reason, current flow will be 0.0
amps and the force motor will regulate maximum throttle signal fluid
pressure. This creates maximum line pressure to prevent any apply
components from slipping until the condition can be corrected.

Approximately every 20 seconds the TCM pulses the force motor at
either maximum (100% duty cycle) or minimum current flow (0%
duty cycle) depending on the force motor operating conditions. These
pulses function to prevent possible contamination from sticking the
force motor valve or plunger in any given position.

➤

THROTTLE
SIGNAL
FLUID

At maximum throttle, the duty cycle is a minimum and current flow
approaches 0.1 amps (always de-energized or OFF as shown in the
drawing). Therefore, the magnetic field is a minimum and spring force
holds the plunger, armature and valve to the left (with respect to the
drawing) against throttle signal fluid pressure acting on the end of the
valve. This closes the exhaust port and opens the throttle signal fluid
circuit to feed limit fluid, creating maximum throttle signal fluid pressure.

Throttle signal fluid pressure also acts on the accumulator valve to
increase accumulator pressure, and apply rate of the clutches and
bands, as throttle angle increases. Remember that with greater accumulator fluid pressure there is less cushion for clutch apply fluid.

ARMATURE SPRING

➤

➤

At minimum throttle (idle), the duty cycle is a maximum and current
flow approaches 1.1 amps (always energized - ON). This keeps the
armature forced against the plunger and compressing the spring. Therefore, throttle signal fluid pressure acting on the end of the force motor
valve moves the valve towards the armature and blocks the feed limit
fluid circuit. The throttle signal fluid circuit is then open to an exhaust
port and throttle signal fluid pressure is at minimum.

➤

EXHAUST

➤

Current flow to the force motor coil creates a magnetic field that
attracts the armature, thereby moving the plunger to the right (with
respect to the drawing) against spring force. Note that the force motor
is assembled with some transmission fluid inside. This fluid assists the
damper spring in cushioning the armature movement.

VALVE

➤ ➤

The duty cycle and amount of current flow to the force motor are
mainly affected by throttle position. Both current flow and duty cycle
are inversely proportional to throttle angle; as throttle angle increases,
the duty cycle is decreased by the TCM which decreases current flow.

FEED
LIMIT
FLUID

➤ ➤

The TCM operates the force motor on a positive duty cycle. This
means that the high (positive) side of the force motor electrical circuit
at the TCM controls the force motor operation. Therefore, the TCM
always provides a ground path for the circuit and continually adjusts
the force motor duty cycle depending on vehicle and transmission
operating conditions. A positive duty cycle is measured as approximately 12 volts on the high (positive) side of the force motor when the
force motor is energized (ON). Figure A shows an example of a 60%
positive force motor duty cycle.

Figure 38

0.9

1.0

1.1

POWER FLOW
This section of the book describes how torque
from the engine is transferred through the Hydramatic 4L30-E transmission allowing the vehicle
to move either in a forward or reverse direction.
The information that follows details the specific
mechanical operation, electrical, hydraulic and
apply components that are required to achieve a
gear operating range.
The full size, left hand pages throughout this
section contain drawings of the mechanical
components used in a specific gear range. Facing
this full page is a half page insert containing a
color coded range reference chart at the top. This
chart is one of the key items used to understand
the mechanical operation of the transmission in
each gear range. The text below this chart provides
a detailed explanation of what is occurring
mechanically in that gear range.

The full size, right hand pages contain a simplified
version of the Complete Hydraulic Circuit that is
involved for each gear range. Facing this full
page is a half page insert containing text and a
detailed explanation of what is occurring
hydraulically in that gear range. A page number
located at the bottom of the half page of text
provides a ready reference to the complete
Hydraulic Circuits section of this book if more
detailed information is desired.
It is the intent of this section to provide an overall
simplified explanation of the mechanical,
hydraulic and electrical operation of the Hydramatic 4L30-E transmission. If the operating
principle of a clutch, band or valve is unclear,
refer to the previous sections of this book for
individual components descriptions.

Figure 39

41

PARK

PARK

Engine Running

Engine Running
SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

➤

➤

➤

➤

NO POWER
TRANSMITTED TO
DIFFERENTIAL
ASSEMBLY

1-2 / 3-4
SOL
N.C.

2-3
SOL
N.O.

OFF

ON

OVERDRIVE
ROLLER
CLUTCH

LD = LOCKED IN DRIVE

OVERRUN
CLUTCH

FOURTH
CLUTCH

THIRD
CLUTCH

REVERSE
CLUTCH

SECOND
CLUTCH

PRINCIPLE
SPRAG
ASSEMBLY

BAND
ASSEMBLY

APPLIED
FW = FREEWHEELING

NE = NOT EFFECTIVE

The Hydra-matic 4L30-E automatic transmission requires a constant supply of pressurized fluid to cool and lubricate the components throughout the unit. It also requires a holding force be
applied to the bands and clutches to obtain the various gear
ranges. The oil pump assembly (10) and valve body assemblies
provide for the pressurization and distribution of fluid throughout the transmission.

➤

OVERRUN
CLUTCH
APPLIED

• The oil pump drive gear (201) is keyed to the torque converter
hub.
• The torque converter assembly (1) is connected to the engine
through the engine flywheel and rotates at engine speed. Therefore, the oil pump drive gear also rotates at engine speed.
• The fluid circulating inside the converter creates a fluid coupling
which drives the converter turbine.

➤

OVERDRIVE
ROLLER CLUTCH
(516)
HOLDING

➤

POWER FROM
TORQUE
CONVERTER
(1)

➤

• The turbine shaft (506), splined to both the converter turbine and
the overdrive carrier assembly (525), drives the carrier assembly.
Overrun Clutch Applied

OUTPUT
SHAFT
HELD

TORQUE
CONVERTER
(1)

OIL
PUMP
(10)
STATIONARY TURBINE
SHAFT
(506)

OVERRUN
CLUTCH
APPLIED

OVERDRIVE
CARRIER
ASSEMBLY
(525)

Overdrive Roller Clutch Holding

• The overdrive roller clutch (516), located between the overdrive
carrier and overrun clutch housing, is holding during acceleration. This assists the overrun clutch plates in holding the overrun
clutch housing and overdrive carrier assembly together.

OVERDRIVE
SUN GEAR
OVERDRIVE
(519)
ROLLER CLUTCH
(516)
HOLDING
REACTION
SUN GEAR
(658)

3RD CLUTCH
DRUM ASSEMBLY
(634)

42

2ND CLUTCH
DRUM ASSEMBLY
(618)

BRAKE BAND
(664)
RELEASED

PARKING
LOCK
WHEEL
(668)
HELD

OUTPUT
SHAFT
HELD

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

Figure 40

• The overdrive internal gear drives the intermediate shaft and
third clutch drum (634) at converter turbine speed.
Sprag Clutch Holding

• The sprag clutch (650), located between the 3rd clutch drum and
input sun gear assembly (646), engages and allows the 3rd clutch
drum to drive the input sun gear.
• The input sun gear drives the short pinion gears in the Ravigneaux planetary carrier (653) counterclockwise. The short pinion gears then drive the long pinion gears clockwise.
• With the brake band (664) released, the long pinion gears drive
the reaction sun gear (658) and reaction sun drum (659) counterclockwise, thereby terminating power flow.
Parking Pawl Engaged

REACTION
SUN DRUM
(659)
INPUT
SUN GEAR
ASSEMBLY
(646)

• With the overrun clutch housing, sun gear and carrier assembly
rotating at the same speed, the pinion gears do not rotate on their
pins. The pinion gears act as wedges to drive the overdrive
internal gear at the same speed as the overdrive carrier and sun
gear. Therefore, power flow through the overdrive gear set is a
1:1 direct drive gear ratio.

OVERDRIVE
INTERNAL
GEAR
(528)

TURBINE
SHAFT
(506)

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

• The overrun clutch plates (520-522) are applied and lock the
overrun clutch housing (510) to the overdrive carrier assembly.
• The overdrive sun gear (519) is splined to and driven by the
overrun clutch housing inner hub.
• The overdrive carrier pinion gears are in mesh with both the
overdrive internal gear (528) and overdrive sun gear.

PARKING
LOCK
ACTUATOR
ASSEMBLY
(56)
PARKING
LOCK
PAWL
(54)
ENGAGED

• The manual selector shaft (61) and manual valve (326) are in the
Park (P) position. The parking lock actuator assembly (56) engages the parking lock pawl (54) with the teeth on the parking
lock wheel (668).
• The parking lock wheel is splined to the output shaft. The parking pawl holds both components stationary and the vehicle cannot move.

Note: The vehicle should be completely stopped before selecting Park range or internal damage to the transmission could
occur. If Park range is selected while the vehicle is moving, the
parking lock pawl will ratchet in and out of the teeth on the
parking lock wheel (668) until the vehicle slows to approximately 5 km/h (3 mph).

42A

PARK

PARK

Engine Running

Engine Running

When the engine is running, the oil pump draws fluid from the
main case bottom pan (74), through the oil filter (79) and into the
oil pump assembly (10). This fluid is pressurized by the oil pump
and directed into the line fluid circuit. The line circuit supplies
the various hydraulic control components, apply components and
fluid circuits throughout the transmission.

TORQUE
CONVERTER
ASSEMBLY

OVERRUN CLUTCH
ASSEMBLY

PUMP ASSEMBLY
PRESSURE
TAP

➤

Pressure Regulation
➤

• Line pressure from the oil pump assembly is directed to the pressure
regulator valve (208). There line pressure is regulated in response to
throttle signal fluid pressure and pressure regulator valve spring
(207) force.
• Excess line pressure at the pressure regulator valve is fed into the
suction circuit. This fluid is routed back to the suction side of the oil
pump.
• Regulated line pressure flows through the force motor screen assembly (415) and to the feed limit valve (412).
• Line pressure is routed into the feed limit fluid circuit at the feed
limit valve. Feed limit fluid is routed to the variable force motor
solenoid (404).
• The force motor regulates feed limit fluid into throttle signal fluid
pressure in relation to throttle position and other TCM input signals.
• In all gear ranges, throttle signal fluid from the force motor is directed to the following:
- boost valve (205) to help regulate line pressure at the pressure
regulator valve .
- throttle signal accumulator piston (214) to dampen the pressure
irregularities in the throttle signal fluid circuit.
- 1-2 accumulator control valve (318) and 3-4 accumulator control
valve (409) to help control shift feel.

➤
➤

➤

SUCTION

RELEASE
➤

APPLY

➤
➤

➤
➤

➤

➤

APPLY

RELEASE

➤

EX

➤ LINE

1-2
EX
➤
EX

LER

COOLER

➤

TO COOLER
APPLY
LINE

➤

EX

RELEASE

➤

EX
➤

➤

OVERDRIVE LUBE

CONV CL CONTROL

➤

SOL SIG

➤

➤

SOLENOID SIGNAL

➤

➤

SOLENOID FEED

➤
➤

➤
➤

➤
➤

➤

SUCTION
➤

THROTTLE SIGNAL

➤

LINE
➤
➤

➤

➤

➤

EX

LINE

➤

➤
➤ LINE

➤

CONV IN

➤

LUBE TO
OVERDRIVE
ASSEMBLY

➤

LINE

➤

➤

SPIRAL
CAPILLARY
RESTRICTION

➤

➤

SOL SIGNAL

TCC
SOLENOID

FILTER

➤

N.C.

OFF

BOTTOM PAN

➤

FORCE MOTOR
SCREEN

LUBE TO
CENTER
SUPPORT

➤

OVERDRIVE LUBE ➤

➤
➤

➤

FEED LIMIT
➤

COO

SUCTION

➤

FEED LIMIT

➤
EX

EX

TO

➤

LINE

EX

➤

FEED LIMIT
THROTTLE SIG

➤

➤

THROTTLE SIG

➤

➤

4TH CL FD 2
➤

FORCE
MOTOR
SOLENOID

➤

➤

4TH CL

THROTTLE SIG ➤

➤

➤

➤

EX

THROTTLE SIGNAL
ACCUMULATOR
➤

CONV IN

LINE

➤

D32

➤

D32

➤

➤

REV

➤

1-2

LINE
R321
1-2
➤

LINE

REVERSE
R321
REV

➤
➤

EX

P RN D 3 2 1

➤

➤

SUCTION
LINE

LINE

EX

➤

➤

EX

MANUAL VALVE

➤
➤

BOOST PRESSURE REGULATOR

CONVERTER IN

➤

➤

➤

➤

➤

THROTTLE SIGNAL

➤

➤

➤

CAPILLARY
RESTRICTION

➤

➤

42B

➤

OVERRUN LOCKOUT

➤

COMPLETE HYDRAULIC CIRCUIT
Page 68

MAIN CASE LUBE ➤

OVERRUN CL

Overrun Clutch Applies

• Line pressure from the pressure regulator valve also flows through
the overrun lockout valve (705) and into the overrun clutch fluid
circuit. The overrun lockout valve is held in position by spring force.
• Overrun clutch fluid pressure is routed to the overrun clutch piston
(513) to apply the overrun clutch plates (520, 522).
• Line pressure is blocked at the manual valve (326). All other fluid
circuits at the manual valve are open to exhaust.
• The 1-2/3-4 shift solenoid is de-energized (OFF) and the 2-3 shift
solenoid is energized (ON). However, with the manual valve blocking line pressure, no fluid acts on the shift valves.

➤

➤

➤

• Fluid exits the converter through the apply fluid circuit, passes through
the converter clutch control valve and enters the cooler fluid circuit.
• Cooler fluid flows through the transmission fluid cooler in the radiator and into the main case lube fluid circuit. This fluid cools and
lubricates the components in the main case (36). Refer to page 90 for
a complete drawing of the lubrication fluid circuits.
• Lubrication for the overdrive components is provided through the
overdrive lube fluid circuit. This circuit is fed by ‘converter in’ fluid
through an orifice.

➤

LINE

➤

➤

Lubrication Circuits

➤

➤

➤

➤

Converter Clutch Circuit

• Line pressure enters the ‘converter in’ fluid circuit through the pressure regulator valve and is routed to the converter clutch control
valve (210).
• Spring force holds the converter clutch control valve in the release
position. ‘Converter in’ fluid is routed through the valve and into the
release fluid circuit.
• Release fluid is directed between the torque converter cover and
pressure plate to keep the torque converter clutch (TCC) released
and fill the converter with fluid. This release fluid unseats the converter clutch apply checkball (504) located in the turbine shaft.

OVERRUN CL
➤

LINE

Figure 41

➤

43

REVERSE

REVERSE
POWER FROM
TORQUE
CONVERTER
(1)

OVERDRIVE
ROLLER CLUTCH
(516)
HOLDING

OVERRUN
CLUTCH
APPLIED

REVERSE
CLUTCH
APPLIED

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

RING GEAR
(630)
HELD

POWER TO
DIFFERENTIAL
ASSEMBLY

1-2 / 3-4
SOL
N.C.

2-3
SOL
N.O.

OVERDRIVE
ROLLER
CLUTCH

OVERRUN
CLUTCH

OFF

ON

LD

APPLIED

LD = LOCKED IN DRIVE

FOURTH
CLUTCH

FW = FREEWHEELING

THIRD
CLUTCH

REVERSE
CLUTCH
APPLIED

SECOND
CLUTCH

PRINCIPLE
SPRAG
ASSEMBLY

BAND
ASSEMBLY

LD

NE = NOT EFFECTIVE

➤

• The manual selector shaft (61) and manual valve (326) are in the
Reverse (R) position.

➤

➤

➤

➤

➤

In Reverse (R), torque from the engine is multiplied through the
torque converter (1) and transmission gear sets to the vehicle’s
drive shaft and rear axle. The planetary gear sets operate in
reduction and also reverse the direction of input torque to achieve
a reverse gear ratio of approximately 2.00:1.

➤

➤

• Engine torque is transmitted from the torque converter turbine to
the third clutch drum (634) in the same manner as Park (P) range:
The overrun clutch plates (520-522) are applied and there is a 1:1
direct drive gear ratio through the overdrive planetary gear set.
• Also, as in Park range, the overdrive roller clutch (516) remains
locked in drive. However, the overrun clutch plates function as
the primary holding force for transferring engine torque.
• The overdrive internal gear drives the intermediate shaft and
third clutch drum (634) at converter turbine speed.
• The sprag clutch (650), located between the 3rd clutch drum and
input sun gear assembly (646), remains engaged and allows the
3rd clutch drum to drive the input sun gear.

OVERRUN
CLUTCH
APPLIED

OVERDRIVE
CARRIER
ASSEMBLY
(525)

OVERDRIVE
INTERNAL
GEAR
(528)

MAIN
CASE
(36)

REVERSE
CLUTCH
APPLIED

RING GEAR
(630)
HELD

• The input sun gear drives the short pinion gears in the Ravigneaux planetary carrier (653) counterclockwise. The short pinion gears then drive the long pinion gears clockwise.
Reverse Clutch Applied

• The reverse clutch plates (614-617) are applied and hold the 2nd
clutch drum assembly (618) stationary to the main transmission
case (36).
• The ring gear (630), splined to the long pinions, is also splined to
the 2nd clutch drum and is held stationary.
• The long pinion gears, rotating clockwise, walk counterclockwise around the stationary ring gear. This drives the carrier assembly and output shaft in a reverse direction.
• The band remains released and the reaction sun gear (658) and
reaction sun drum (659) freewheel as in Park.

TURBINE
SHAFT
(506)

OVERDRIVE
SUN GEAR
OVERDRIVE
(519)
ROLLER CLUTCH
(516)
HOLDING

3RD CLUTCH
DRUM ASSEMBLY
(634)

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

TURBINE
SHAFT
(506)

REACTION
SUN GEAR
(658)

OUTPUT
SHAFT

2ND CLUTCH
DRUM ASSEMBLY
(618)
HELD

BRAKE BAND
(664)
RELEASED

Coast Conditions

• When the throttle is released in Reverse and engine RPM decreases, power from vehicle speed drives the output shaft faster
than engine torque is driving the 3rd clutch drum (634). Therefore, the short pinion gears - driven by vehicle speed - drive the
input sun gear assembly (646) faster than the 3rd clutch drum is
rotating. This causes the input sun gear assembly to overrun the
sprag clutch (650), thereby allowing the vehicle to coast freely.

Note: Reverse Lockout is not available on all applications. For
these models, the reverse lockout and reverse shuttle valves are
not included and the TCC solenoid is fed by second clutch fluid.

REACTION
SUN DRUM
(659)
INPUT
SUN GEAR
ASSEMBLY
(646)

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

44A

44

Figure 42

REVERSE

REVERSE

When the gear selector lever is moved to the Reverse (R) position, the manual valve (326) also moves and line pressure enters
the R321 fluid circuit.

Reverse Clutch Applied
TORQUE
CONVERTER
ASSEMBLY

➤

SOL SIG

➤

EX

➤
➤

➤

➤

➤

TO COOLER
APPLY
LINE

➤

EX

RELEASE

CONV CL CONTROL

SOL SIG

REV
2ND CL

➤

EX
➤

THROTTLE SIGNAL

➤

LINE

➤

➤
➤
➤

➤

➤

➤

TO COOLER
APPLY

➤

EX

REV CL
➤ REVERSE

➤
➤

➤ LINE

➤

EX

➤

SOLENOID SIGNAL

➤
➤

➤

➤

REV CL

4TH CL FD 2

➤

➤

4TH CL FD 2

LINE
➤

1-2
EX
➤

LINE

➤

SOL SIGNAL

➤

CONV IN
➤

REVERSE
SHUTTLE
VALVE

➤

N.C.

SOLENOID FEED

REVERSE

THROTTLE SIGNAL
EX ACCUMULATOR

LINE

➤

➤

➤

➤

D32

➤

➤

LINE

➤

Figure 43

LINE
R321
1-2

➤

REV

REVERSE

➤

➤

LINE
➤

LINE
➤

SUCTION
➤
LINE

➤

➤
➤

➤

➤

➤

➤

EX

➤

LINE (From Pump)

P RN D 3 2 1

➤

CONVERTER IN

➤

EX

➤

➤

EX

MANUAL VALVE

➤

BOOST PRESSURE REGULATOR

D32

➤

REV

1-2

➤

➤

THROTTLE SIGNAL

➤
➤

CAPILLARY
RESTRICTION

SOL FEED

➤
➤

OFF

TCC
SOLENOID

➤

➤

➤

FORCE MOTOR
SCREEN

EX

TCC
SOLENOID

➤

EX

➤

➤

FEED LIMIT

FEED LIMIT
➤

ON

➤

EX

EX

➤

REV LOCKOUT

SOL SIGNAL

➤

➤

TRT SIG

➤

LINE
➤

N.C.

EX

FEED LIMIT
THROTTLE SIG

➤

➤

➤ REV

EX

➤

➤

FORCE
MOTOR
SOLENOID

LINE

CONV CL CONTROL
➤

➤

➤ EX ➤

CONV IN
RELEASE

➤

➤

4TH CL

➤

APPLY

➤
➤

RELEASE

OVERRUN CL ➤

➤

REV

SOL SIG

CL ➤
REVERSE

➤

➤

THROTTLE SIG ➤

➤

➤

44B

COMPLETE HYDRAULIC CIRCUIT
Page 70

➤

OVERRUN LOCKOUT

Reverse Locked Out (inset in Figure 43)

Note: The hydraulic system in Reverse operates in the same manner as Park (P) range except as described above. In each of the
following gear ranges, most of the hydraulic and electrical systems
explanation is limited to what changes from the previous range.
Therefore, if a component or circuit is not explained, it functions
similar to the range on the previous page. However, some explanations are repeated for clarity and continuity.

REV LOCKOUT

➤

➤

➤

• Reverse fluid is also directed to the boost valve (205) at the end of
the pressure regulator valve (208). Reverse fluid pressure moves
these valves to increase line pressure for the additional torque requirements in Reverse.
• Throttle signal fluid pressure also acts on the boost valve to help
determine line pressure in Reverse depending on throttle position
and other TCM input signals.
• The 1-2/3-4 shift solenoid is de-energized (OFF) and the 2-3 shift
solenoid is energized (ON) - as in Park range. Also, line pressure
remains blocked by the manual valve, thereby preventing fluid pressure from acting on the shift valves (see Note below).

• Solenoid feed fluid enters the solenoid signal fluid circuit through
the open converter clutch solenoid.
• Solenoid signal fluid is directed to the reverse lockout valve. Solenoid signal fluid pressure, in addition to spring force, closes the
valve against orificed reverse fluid pressure.
• Reverse fluid is blocked from entering the reverse clutch fluid circuit. Also, the reverse clutch fluid circuit is open to an exhaust port
at the reverse lockout valve. Therefore, the reverse clutch cannot
apply. During ‘Reverse Lock Out’, the transmission operates in a
Neutral condition.
• Solenoid signal fluid pressure is also directed to the converter clutch
control valve and shifts the valve to the apply position. Therefore,
the converter clutch is applied when the transmission is in a ‘Reverse Lock Out’ condition.
• When vehicle speed decreases sufficiently, the TCM will de-energize the TCC solenoid. This opens the solenoid and allows solenoid
signal fluid to exhaust, the reverse clutch to apply and the TCC to
release.

➤ EX ➤

REV CL

➤

Pressure Regulation

A ‘Reverse Lock Out’ condition is available on some applications
to prevent the transmission from applying the reverse clutch, and
possibly damaging the transmission components, when the vehicle
is moving forward. If Reverse (R) is selected with vehicle speed
above approximately 12 km/h (7 mph), the TCM will energize
(turn ON) the converter clutch solenoid. Remember that the mode
switch [located on the selector shaft (61)] signals the TCM that the
transmission is in Reverse (R). This opens the normally closed
solenoid and the following events occur:

Reverse Locked Out

➤

• R321 fluid flows through an orifice, back through the manual valve
and into the reverse fluid circuit.
• Reverse fluid pressure seats the reverse shuttle valve (85) against the
2nd clutch fluid circuit and enters the solenoid feed fluid circuit.
• With the vehicle stationary the TCM keeps the converter clutch
solenoid de-energized (OFF). This prevents solenoid feed fluid from
entering the solenoid signal fluid circuit. However, if the vehicle is
moving forward above approximately 12 km/h (7 mph) when Reverse is selected, the reverse clutch is prevented from applying (see
Reverse Locked Out below).
• Reverse fluid is orificed to the end of the reverse lockout valve
(706). This fluid pressure moves the valve against spring force and
reverse fluid at the middle of the valve enters the reverse clutch fluid
circuit.
• Reverse clutch fluid pressure is directed to the reverse clutch piston
(610) to apply the reverse clutch plates (614- 616).

REVERSE CLUTCH ASSEMBLY

➤

Reverse Clutch Applies

OVERRUN CLUTCH
ASSEMBLY

➤

45

NEUTRAL

NEUTRAL

Engine Running

Engine Running
POWER FROM
TORQUE
CONVERTER
(1)

OVERDRIVE
ROLLER CLUTCH
(516)
HOLDING

OVERRUN
CLUTCH
APPLIED

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

NO POWER
TRANSMITTED TO
DIFFERENTIAL
ASSEMBLY

1-2 / 3-4
SOL
N.C.

2-3
SOL
N.O.

OFF

ON

OVERDRIVE
ROLLER
CLUTCH

LD = LOCKED IN DRIVE

OVERRUN
CLUTCH

FOURTH
CLUTCH

THIRD
CLUTCH

REVERSE
CLUTCH

SECOND
CLUTCH

PRINCIPLE
SPRAG
ASSEMBLY

BAND
ASSEMBLY

APPLIED
FW = FREEWHEELING

NE = NOT EFFECTIVE

Mechanical power flow in Neutral (N) is identical to Park (P)
range.

➤

➤

• Engine torque is transmitted through the 3rd clutch drum assembly (634), sprag clutch assembly (650), input sun gear assembly
(646), the short and long Ravigneaux pinion gears, the reaction
sun gear (658) and reaction sun drum (659).

➤

➤

➤

➤

➤

• The overrun clutch plates (520-522) are applied, the overdrive
roller clutch (516) is holding and there is a 1:1 direct drive gear
ratio through the overdrive planetary gear set.

• As in Park range, the reaction sun gear and reaction drum are free
to rotate with the brake band released, and power flow is terminated.

➤

Parking Lock Pawl Disengaged

• The manual selector shaft (61) and manual valve (326) are in the
Neutral (N) position - see Note below.
• The parking lock actuator assembly (56) releases the parking
lock pawl (54).

OUTPUT
SHAFT

TORQUE
CONVERTER
(1)

OIL
PUMP
(10)
STAIONARY TURBINE
SHAFT
(506)

OVERRUN
CLUTCH
APPLIED

OVERDRIVE
CARRIER
ASSEMBLY
(525)

Refer to the appropriate Service Manual for the proper manual
linkage adjustment procedures.

OVERDRIVE
SUN GEAR
OVERDRIVE
(519)
ROLLER CLUTCH
(516)
HOLDING
REACTION
SUN GEAR
(658)

3RD CLUTCH
DRUM ASSEMBLY
(634)

46

2ND CLUTCH
DRUM ASSEMBLY
(618)

BRAKE BAND
(664)
RELEASED

PARKING
LOCK
WHEEL
(668)
RELEASED

OUTPUT
SHAFT

REACTION
SUN DRUM
(659)
INPUT
SUN GEAR
ASSEMBLY
(646)

• The parking lock wheel, Ravigneaux carrier assembly and output
shaft (653) are free to rotate, allowing the vehicle to roll freely.

Note: The manual linkage must be adjusted properly so the
indicator quadrants in the vehicle correspond with the range
selector lever (60) in the transmission. If not adjusted properly,
an internal leak between fluid passages at the manual valve may
cause a clutch or band to slip or cause the transmission not to
hold in Park.

OVERDRIVE
INTERNAL
GEAR
(528)

TURBINE
SHAFT
(506)

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

• The parking lock pawl spring (53) disengages the parking pawl
from the teeth on the parking lock wheel (668).

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

Figure 44

PARKING
LOCK
ACTUATOR
ASSEMBLY
(56)
PARKING
LOCK
PAWL
(54)
DISENGAGED

46A

NEUTRAL

NEUTRAL

Engine Running

Engine Running
When the gear selector lever is moved to the Neutral (N) position, the hydraulic and electrical systems operate identical to
Park (P) range. However, the following changes occur if Neutral is selected when the vehicle is operating in Reverse (R):

TORQUE
CONVERTER
ASSEMBLY

OVERRUN CLUTCH
ASSEMBLY

REVERSE CLUTCH ASSEMBLY

➤

Reverse Clutch Releases

• The manual valve (326) blocks line pressure from entering the
R321 fluid circuit.
➤
➤

RELEASE

OVERRUN CL ➤

➤

➤

APPLY

➤
➤

➤

• Reverse clutch fluid, which was fed by reverse fluid, exhausts
through the reverse lockout valve (706).

➤

➤

REVERSE

REV CL ➤
REVERSE

➤

REV CL

➤ EX ➤

➤

➤

➤

➤

➤
➤

➤

➤

➤
➤

➤

➤

➤
➤

➤

➤
➤

➤

➤

➤

➤

➤

TO COOLER
APPLY
LINE

REVERSE

➤

LINE

➤

➤

➤

➤

➤

THROTTLE SIGNAL
EX ACCUMULATOR

➤

D32

Figure 45

➤

LINE

➤

➤

LINE
R321
1-2
➤

➤

➤ REV ➤

➤
➤

➤ REVERSE ➤

LINE

➤

LINE

SUCTION
LINE
➤

➤

➤

EX

➤

➤
➤

P RN D 3 2 1

➤

➤

➤

➤

➤

EX

MANUAL VALVE

➤

➤

D32

➤

➤

EX

➤

➤

➤

➤

➤

➤

BOOST PRESSURE REGULATOR

➤

➤

➤

➤

➤

➤

➤

➤

REV ➤

1-2

➤
➤

CAPILLARY
RESTRICTION

➤

EX

EX
➤

➤

➤

➤

➤

FEED ➤

RELEASE

SOL SIG

➤

➤

SOLENOID SIGNAL

2ND CL

➤ REVERSE ➤

THROTTLE SIGNAL

➤

LINE

➤ LINE

EX

➤

LINE

➤

➤SOLENOID

➤

SOL SIGNAL

➤

➤

➤

TCC
SOLENOID

➤

CONV CL CONTROL

➤

N.C.

OFF

LINE (From Pump)

SOL SIG

4TH CL FD 2

4TH CL FD 2

➤REVERSE ➤

➤
➤

LINE

1-2
EX

➤

➤

➤

➤

EX

➤

➤

➤

CONV IN
➤

➤

REVERSE
SHUTTLE
VALVE

➤
➤

➤

FORCE MOTOR
SCREEN

➤

➤
➤

➤

➤

➤

EX

CONVERTER IN

➤

➤

➤

FEED LIMIT

FEED LIMIT
➤

➤

➤

➤

➤

➤

➤

➤
EX

THROTTLE SIGNAL

➤

REV LOCKOUT

➤

LINE

EX

➤

➤

➤

FEED LIMIT
THROTTLE SIG

➤

THROTTLE SIG

➤

➤

- the 1-2/3-4 shift solenoid is de-energized (OFF).
- the 2-3 shift solenoid is energized (ON).
- line pressure remains blocked by the manual valve, thereby
preventing fluid from acting on the shift valves.
- the overrun clutch is applied.

➤

➤

FORCE
MOTOR
SOLENOID

• Similar to Park (P) and Reverse (R):

➤

➤

➤

THROTTLE SIG ➤

➤

➤

Note: If Neutral is selected when ‘Reverse Lock Out’ is in effect
(see page 44B), the TCM will de-energize (turn OFF) the TCC
solenoid. This allows solenoid signal fluid to exhaust through
the solenoid, thereby releasing the converter clutch.

➤

• Reverse fluid also exhausts from the boost valve (205) and line
pressure returns to the normal operating range.

➤

OVERRUN LOCKOUT

➤

EX

4TH CL

• Solenoid feed fluid, also fed by reverse fluid, exhausts from the
TCC solenoid, past the reverse shuttle valve (85), into the reverse
fluid circuit and past the manual valve.

46B

➤
➤

• With reverse clutch fluid exhausted from the reverse clutch piston (610), the reverse clutch plates (614- 616) are released.

COMPLETE HYDRAULIC CIRCUIT
Page 72

REV CL

➤

➤

➤

➤

➤

• Reverse fluid exhausts from the reverse lockout valve (706)
and spring force moves the valve to the closed position.

➤

• The R321 and reverse fluid circuits are open to exhaust at the
manual valve.

➤

➤

47

DRIVE RANGE - FIRST GEAR

DRIVE RANGE - FIRST GEAR
OVERRUN
CLUTCH
APPLIED

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

REACTION
POWER TO
SUN DRUM
DIFFERENTIAL
(659)
ASSEMBLY
HELD
REACTION
BRAKE BAND
SUN GEAR
(664)
(658)
APPLIED
HELD

➤

➤

➤

➤

1-2 / 3-4
SOL
N.C.

2-3
SOL
N.O.

OVERDRIVE
ROLLER
CLUTCH

OVERRUN
CLUTCH

OFF

ON

LD

APPLIED

LD = LOCKED IN DRIVE

FOURTH
CLUTCH

FW = FREEWHEELING

THIRD
CLUTCH

REVERSE
CLUTCH

SECOND
CLUTCH

PRINCIPLE
SPRAG
ASSEMBLY

BAND
ASSEMBLY

LD

APPLIED

NE = NOT EFFECTIVE

In Drive Range (D) - First Gear, torque from the engine is
multiplied through the torque converter and transmission gear
sets to the vehicle’s drive shaft. The planetary gears operate in
reduction to achieve a First gear starting ratio of approximately
2.40:1.
• The manual selector shaft (61) and manual valve (326) are in the
Drive Range position (D).

➤

OVERDRIVE
ROLLER CLUTCH
(516)
HOLDING

➤

POWER FROM
TORQUE
CONVERTER
(1)

➤

➤

• Engine torque is transmitted to the 3rd clutch drum assembly
(634) from the converter turbine in the same manner as Park,
Reverse and Neutral: The overrun clutch plates (520-522) are
applied, the overdrive roller clutch is holding and there is a 1:1
direct drive ratio through the overdrive gear set.
• The sprag clutch (650), located between the 3rd clutch drum and
input sun gear assembly (646), engages and allows the 3rd clutch
drum to drive the input sun gear.
• The input sun gear drives the short pinion gears in the Ravigneaux planetary carrier (653) counterclockwise. The short pinion gears then drive the long pinion gears clockwise.
Brake Band Applied

• The brake band (664) is applied and holds the reaction sun drum
(659) stationary to the main transmission case (36).

OVERRUN
CLUTCH
APPLIED

OVERDRIVE
CARRIER
ASSEMBLY
(525)

RING
GEAR
(630)

OVERDRIVE
INTERNAL
GEAR
(528)

• The reaction sun gear (658), which is splined to the reaction sun
drum, is also held stationary.
• The long pinions, rotating clockwise, walk clockwise around the
stationary reaction sun gear. This drives the planetary carrier and
output shaft assembly (653) clockwise in a First gear reduction
of approximately 2.40:1.
• Also, the long pinions drive the ring gear (630) and 2nd clutch
drum (618) clockwise. However, the 2nd and reverse clutches
are released and these components do not affect power flow.
Coast Conditions

TURBINE
SHAFT
(506)

OVERDRIVE
SUN GEAR
OVERDRIVE
(519)
ROLLER CLUTCH
(516)
HOLDING

REACTION
SUN GEAR
(658)
HELD

48

As vehicle speed increases, less torque multiplication is needed
for maximum efficiency. Therefore, it is desirable to shift the
transmission to a lower gear ratio, or Second gear.

OUTPUT
SHAFT

REACTION
SUN DRUM
(659)
HELD
INPUT
SUN GEAR
ASSEMBLY
(646)

BRAKE BAND
(664)
APPLIED

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

➤

3RD CLUTCH
DRUM ASSEMBLY
(634)

SPRAG CLUTCH
ASSEMBLY
(650)
DRIVING

TURBINE
SHAFT
(506)

2ND CLUTCH
DRUM ASSEMBLY
(618)

• As in Reverse, when the throttle is released and engine RPM
decreases, power from vehicle speed drives the output shaft faster
than engine torque is driving the 3rd clutch drum (634). Therefore, the short pinion gears drive the input sun gear assembly
(646) faster than the 3rd clutch drum is rotating. This causes the
input sun gear to overrun the sprag clutch assembly (650) and
allows the vehicle to coast freely.

SERVO
ASSEMBLY
APPLIED

48A
Figure 46

DRIVE RANGE - FIRST GEAR

DRIVE RANGE - FIRST GEAR

When the gear selector lever is moved to the Drive Range (D)
position, the manual valve (326) also moves and line pressure
enters the D32 fluid circuit. Also, the mode switch located on
the selector shaft (61) signals the TCM that the transmission is
in Drive Range.

OVERRUN CLUTCH
ASSEMBLY
➤

• D32/1-2 fluid flows through the Pulse Width Modulated (PWM)
solenoid screen (324). This D32/1-2 fluid enters the servo apply
fluid circuit through both an orifice and the PWM band apply
solenoid (323).

1-2
ACCUMULATOR
ASSEMBLY

➤

➤

➤

2ND CLUTCH

• D32 fluid pressure seats the D32 shuttle valve (85) against the
empty 1-2 fluid circuit. D32 fluid enters the D32/1-2 fluid circuit.

SERVO APPLY
SERVO REL

Brake Band Applies

➤

➤

➤

4TH CL
EX

➤

➤

➤

3RD CL FEED

➤

➤

➤

➤
EX

D 3 2/1-2

➤

SERVO APPLY

2-3 SHIFT

1-2 ACCUM
D 3 2/1-2
1-2 ACCUM
EX

➤

➤

EX

EX

➤

PWM
BAND
ON/OFF CONTROL
SOLENOID
N.O.

EX

D 3 2/1-2

➤

SERVO REL
D32 ➤

➤

➤
➤

4TH CL FD 1

➤

EX

ON

CONTROL 1-2 ACCUM

➤

➤

PWM SOLENOID
SCREEN

D32

➤

LINE

➤

➤

➤

LINE

Figure 47

EX
1-2

EX

LINE
R321
1-2

P RN D 3 2 1

➤

LINE (From Pump)

D32

MANUAL VALVE

➤

LINE

SUCTION
LINE

➤

➤

➤

REV

➤

➤

➤

CONVERTER IN

EX

D32
➤

BOOST PRESSURE REGULATOR
➤

1-2

➤

➤

➤

➤

REV
R321
REVERSE

➤

➤

D32
SHUTTLE
VALVE

➤

THROTTLE SIGNAL

THROTTLE SIGNAL
ACCUMULATOR

➤

EX

D 3 2/1-2

➤

➤

➤
➤

CAPILLARY
RESTRICTION

D 3 2/1-2

➤
➤

➤

➤

• D32 fluid is also routed to and blocked by the 2-3 shift valve
(308) in preparation for a 2-3 upshift.

48B

EX

EX

➤
SOLENOID
N.O.

EX

➤

➤
➤

LINE

THROTTLE SIGNAL

➤

EX

➤
EX

➤ LINE

➤

➤

SERVO REL
4TH CL FD 1

D 3 2/1-2
➤

FORCE MOTOR
SCREEN

➤

➤

➤

➤

FEED LIMIT

➤

1-2 & 3-4 SHIFT

➤

EX

➤

EX

LINE

SOLENOID
N.C.

OFF

FEED LIMIT

➤

THROTTLE SIGNAL

➤

4TH CL FEED 2

➤

LINE

• D32/1-2 fluid is blocked by both the 1-2/3-4 shift valve and the
2-3 shift valve in preparation for the 1-2 and 3-4 upshifts respectively.

COMPLETE HYDRAULIC CIRCUIT
Page 74

➤

➤

1-2 REG

• D32/1-2 fluid feeds both of the shift solenoid assemblies:

EX

➤

➤

FEED LIMIT
THROTTLE SIG

➤

➤

2ND CLUTCH

Shift Solenoids

➤

1-2 ACCUM

➤
➤

➤

➤

FORCE
MOTOR
SOLENOID

• 1-2 accumulator fluid fills the 1-2 accumulator in preparation for
a 1-2 upshift.

➤

➤

➤

➤

4TH CL FD 2

4TH CL FD 2

LINE
➤

1-2
EX

THROTTLE SIG ➤

➤

• D32/1-2 fluid is also directed to the 1-2 accumulator valve (320).
The 1-2 accumulator valve regulates D32/1-2 fluid into the 1-2
accumulator fluid circuit in relation to throttle signal fluid pressure and, on some models, 1-2 accumulator control spring (319)
force.

➤

Note: Refer to page 39 for a complete description of the PWM
band apply solenoid operation.

- The 2-3 shift solenoid (307), which is normally open, remains
energized (ON) by the TCM and blocks D32/1-2 fluid pressure from acting on the end of the 2-3 shift valve (308). This
allows spring force to keep the valve in the First and Second
gear position.

SERVO PISTON
ASSEMBLY

OVERRUN LOCKOUT

• The PWM band apply solenoid regulates servo apply fluid pressure depending on vehicle operating conditions as determined by
the TCM. This regulation controls the rate at which servo apply
fluid pressure increases and the band assembly applies.

- The normally closed 1-2/3-4 shift solenoid (303) remains deenergized (OFF) and blocks D32/1-2 fluid pressure from acting on the end of the 1-2/3-4 shift valve (304). This allows
spring force to keep the valve in the First and Fourth gear
position.

➤

➤

OVERRUN CL

➤

➤

• Servo apply fluid pressure is routed to the apply side of the servo
piston (97). This fluid pressure moves the piston against the force
from the servo cushion (99) and servo return (103) springs, thereby
moving the apply rod (102) and applying the brake band (664).

➤

49

DRIVE RANGE - SECOND GEAR

DRIVE RANGE - SECOND GEAR
POWER FROM
TORQUE
CONVERTER
(1)

OVERDRIVE
ROLLER CLUTCH
(516)
HOLDING

OVERRUN
CLUTCH
APPLIED

SPRAG CLUTCH
ASSEMBLY
(650)
OVERRUNNING

2ND CLUTCH
APPLIED

POWER TO
REACTION
DIFFERENTIAL
SUN DRUM
ASSEMBLY
(659)
HELD
REACTION
BRAKE BAND
SUN GEAR
(664)
(658)
APPLIED
HELD

➤

➤

➤

➤

➤

➤

➤

➤

1-2 / 3-4
SOL
N.C.

2-3
SOL
N.O.

OVERDRIVE
ROLLER
CLUTCH

OVERRUN
CLUTCH

ON

ON

LD

APPLIED

LD = LOCKED IN DRIVE

FOURTH
CLUTCH

FW = FREEWHEELING

THIRD
CLUTCH

REVERSE
CLUTCH

SECOND
CLUTCH

PRINCIPLE
SPRAG
ASSEMBLY

BAND
ASSEMBLY

APPLIED

FW

APPLIED

NE = NOT EFFECTIVE

As vehicle speed increases, input signals from the Vehicle Speed
Sensor (VSS), Throttle Position Sensor (TPS) and other vehicle
sensors are continually changing and being monitored by the
Transmission Control Module (TCM). The TCM processes this
information to determine the precise moment to shift the transmission. In Second gear, the planetary gear sets continue to
operate in reduction at a gear ratio of approximately 1.48:1.
• Engine torque is transmitted to the 3rd clutch drum assembly
(634) from the converter turbine in the same manner as Drive
Range - First Gear: The overrun clutch plates (520-522) are
applied, the overdrive roller clutch is holding and there is a 1:1
direct drive ratio through the overdrive gear set.
2nd Clutch Applied

• The 2nd clutch plates (625-627) are applied and power flow is
transferred from the 3rd clutch drum to the 2nd clutch drum
(618).
• The ring gear (630), which is splined to the 2nd clutch drum,
drives the long pinions in the Ravigneaux carrier assembly (653)
clockwise.
• The brake band (664) remains applied as in First gear and holds
the reaction sun drum (659) stationary to the main transmission
case (36).

OVERRUN
CLUTCH
APPLIED

OVERDRIVE
CARRIER
ASSEMBLY
(525)

RING
GEAR
(630)

OVERDRIVE
INTERNAL
GEAR
(528)

• The reaction sun gear (658), which is splined to the reaction sun
drum, is also held stationary.
• The long pinions, driven by the ring gear, walk clockwise around
the stationary reaction sun gear. This drives the Ravigneaux carrier and output shaft assembly (653) clockwise in a Second gear
reduction of approximately 1.48:1.
Sprag Clutch Overruns

• The long pinions drive the short pinions counterclockwise. The
short pinions then drive the input sun gear assembly (646) clockwise faster than the 3rd clutch drum (634) is rotating. This causes
the input sun gear assembly to overrun the sprag clutch (650).
TURBINE
SHAFT
(506)

Coast Conditions
2ND CLUTCH
APPLIED

OVERDRIVE
SUN GEAR
OVERDRIVE
(519)
ROLLER CLUTCH
(516)
HOLDING

REACTION
SUN GEAR
(658)
HELD

RAVIGNEAUX
PLANETARY
CARRIER
ASSEMBLY
(653)

• Power from vehicle speed attempts to drive the transmission gear
sets through the output shaft faster than engine torque is driving
as an input. However, without an element to overrun, power from
the drive shaft is transferred through the transmission gear sets to
the engine. This causes engine compression to slow the vehicle
when the throttle is released.

As vehicle speed increases, less torque multiplication is needed
to move the vehicle efficiently. Therefore, it is desirable to shift
the transmission to a lower gear ratio, or Third gear.

OUTPUT
SHAFT

REACTION
SUN DRUM
(659)
HELD
INPUT
SUN GEAR
ASSEMBLY
(646)

BRAKE BAND
(664)
APPLIED

➤

3RD CLUTCH
DRUM ASSEMBLY
(634)

SPRAG CLUTCH
ASSEMBLY
(650)
OVERRUNNING

TURBINE
SHAFT
(506)

• In Second gear, neither the overdrive roller clutch (516) nor the
sprag clutch (650) is used to transfer engine torque during acceleration. Therefore, there are no elements to overrun and allow
the vehicle to coast freely when the throttle is released.

SERVO
ASSEMBLY
APPLIED

50A

50

Figure 48



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