Gege Blog 21.1 Michel finaizes Gearbox A (f)

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Gege Blog English –

21.1 – MICHEL FINALIZES GEARBOX “A “ - Michel finalise la boîte "A"

and the list of parts:

( Click image to enlarge)

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For a better understanding of what follows, here is the parts catalog for the box (with the gear lever etc.):

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Friday October 07, 2016

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The gearbox, shipped Tuesday October 4 arrived Thursday 6, thank you TNT. Michel went to get it this Friday, and started his
examination

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Two photos of the steering box , prepared for welding the (belatedly ! discovered ) crack:

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And some views of his new workshop:

Monday October 10, 2016
Today, rectification of the front bronze bush with shoulder, (from Mr Laureau) of the front primary half-shaft. It is the one that
receives the rear end of the crankshaft, and Michel has rectified it to 16 mm ext. so that it fits without tightening in the front
primary half shaft of the "A" which we will use to center the clutch. Its internal diameter is adjusted to 12 mm.

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Michel also machined a new rear bronze bush for the front primary half shaft from the "F" box which will replace that of the
"A". It is extended by 3.5mm

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… to compensate for the play found between the two half primary shafts

He also made a new rear bush receiving the end of the crankshaft.

The half shaft of the "F" gearbox with its new bushes …

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… and its oil-thrower ring nut with the "C" pin:

On the left, the half shaft of the "A" which will be used to center the clutch disc. On the right half shaft of "F", reassembled
with the bearing and the cage

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and here placed in the box (and there is no longer play between the two half primary shafts!)

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Clutch side, it remains to reassemble the flange:

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Wednesday October 12, 2016

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Operating diagram ( click image to enlarge )

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The lower part of the gear lever (sphere and fork control paddle) is really too worn, and Michel prefers to machine a new one
rather than repairing the old one.

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The plan for the CNC machine has been done

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and a simulation of the machining work (watch the program code to the machine at the end of the video ...)

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Section of the cover in current condition, where we can clearly see the wear of the aluminum at the level of the ball joint,
which causes a vertical offset of 4.86 mm of the gear lever; and the consequently inappropriate position of the "Shift lever
pin" (11814, in green). The very shape of this piece is amazing, as well as its supports on the lid. Is it original? In any case, there
is work to make it work rationally and mechanically!

( Click image to enlarge)
October 13, 2016

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For the fork shafts, Michel starts with 12 mm chromed steel bars. The forks now slide freely but without play. Then machining
the end thread, and the locking notches by the "Locking yoke in neutral of the gear change lever" (30196):

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For the position of the notches for locking the sliding gears with the ball, Michel marks the 3 correct positions ( neutral, 1st /
MA for one shaft and neutral, 2nd / direct drive for the other) when the sliding gears are perfectly in place (opposite the
corresponding or interconnected pinions or between the pinions of the intermediate gear):

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Now we have to machine the 6 notches, machine a new yoke 30196 and re-surface the forks to correct the wear caused by the
gear lever ...

Friday October 14, 2016

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Machining of the notches in the new fork shafts:

A "prototype":

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The two shafts completed

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We see here that the first / reverse gear fork will have to be re-surfaced and resized so that its neutral position is positioned
properly ...

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Saturday October 15, 2016

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Re-surfacing forks and rectification:

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Machining of a new "locking yoke ..." (30196) and rectification:

The forks in neutral and the yoke now match perfectly:

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Monday October 17, 2016

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Today, machining of an aluminum "insert" receiving the sphere of the gear lever in the gearbox cover.

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In the foreground, the insert 33 mm outside diameter, spherical machined bottom:

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Machining of the cover to 33 mm in diameter to receive the insert (the diameter of the top of the lid is 34 mm, the 0.5 mm
step is visible ...) .

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The insert in place:

Tuesday October 18, 2016
A beautiful drawing is better than a long speech in order to understand the repair operations of the cover and its accessories

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( Click image to enlarge )

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View of the aluminum insert from the inside of the cover:

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Reworking of the housing (which was completely ovalized) of the "gear change lever lug" (11814) in order to fit a bush:

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And the bush which must still be machined at its ends:

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There are also three elastic pins ensuring the maintenance of the aluminum insert ...

Section (provisional) with the bronze bush (not yet resized), the "ball joint protector" (10235) made of sheet metal, the "shell
spring cap" (10233) to be screwed in and the "ball joint shell" ( 10236):

Saturday October 22, 2016

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New sections showing the different positions of the lever in the front-rear plane ... The lug 11814 (in green) will be held
longitudinally by a "grain" which does not prevent its rotation

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Machining of the rounding of the bronze bush receiving lug 11814:

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Machining a new lower end of gear lever (Accelerated video 5x)

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. "Il Macchina" (video):

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And when the “ macchina a controllo numerico “ is set, it's also easy to make 3!

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Machining of the lower end driving the forks:

On the right, the old lower end badly worn:

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Comparison:

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It remains to reweld on one of the new ones the upper part of the gear lever ...

Sunday October 23, 2016
Small video of the test of this refurbishment. The gear lever is not yet re-welded and is replaced by a tube, and the "antirotation" lug 11814 is temporarily replaced by a piece of shaft machined cylindrically at its end to enter the notch of the
sphere lever:

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On the right new ergot 11814, compared to the old one somewhat worn (and has already been re-surfaced in a previous life
...) . Note that this part is longer than the original one, in order to have a greater reach in the new bronze ring, and thus to
reduce the risk of "barrel" wear of the cylindrical part ...

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Tuesday, October 25, 2016

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New video of very good quality, with re-soldered lever and pin 11814: in place

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Pleasant and precise "clacks", and absence of parasitic play! Wonderful Michel ...
And here, re-surfacing and rectification of ball nut 11498 of the brake drum on transmission

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and the tool "made by Michel" to tighten this to the right torque (but which one ?!):

Tuesday November 1, 2016

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The gear lever ball, made of an indefinable material, is cooked. Michel will therefore (!) Machine a new one out of wood
(which one?) ...

Wednesday, November 2, 2016
First tests, with teak (pending - probably - walnut):

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Maybe a little oval?

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Thursday 03 November 2016

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Second version still in teak to perfect the technique: Video :

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The balls are now perfectly round ...

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And with the new "cap" extending by an internally threaded rod and crossing the ball, and which will be screwed onto the gear
lever:

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and the drawing:

Wednesday 09 November 2016
A beautiful olive root:,

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and Michel's lathe is very surprised to be surprised to be working on that!

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Video :

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The balls are still cylindrical ... But there they are very round!

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Turning the brass cap Video

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Two teak balls (dark) and those in olive (clear) . It's beautiful !

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Friday November 11, 2016

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The latest lock washers (drum at the end of the gearbox and hanging rod from the steering box):

Packaged, and shipped today ...

It's over for this chapter, the rest is here ! (Box "A" is back from Italy ...)

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THE END