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Finally ... Repairing a traction gearbox.

DoubleChevron

Real cars have hydraulics
Do it with the box vertical! Lever the second fixed speed up to insert the half locking collars. A screw driver is useful here!
Thanks Gerry, I had tried that (I think you have told me several times to do it that way :) ). I got a good light and shined in there and tried to see what was going on. I hadn't driven the shaft in far enough so the C washers couldn't sit in. A couple of gentle whacks with the rubber mallet on the pinion ..... and they the C clip wouldn't fit at all ..... The gap was to narrow. So a gentle tap on the nose of the shaft create the exact clearance to get the C washers back in (Let me guess, I'll need to do this another 20times before its finally done .... so will have plenty of practice!). The dial gauge arrived in the post yesterday, so hopefully over the next couple of weeks I can bolt this 'box back into the car ..... Then find what else is worn out and broken on it :D

Maybe the manufacturer didn't think some nutter would be still trying to drive the car 70years down the track!

seeya
Shane L.
 

gerrypro

1000+ Posts
Yes it is a time consuming process! Good to have a dial gauge, but also good to double check with the feelers as well!
How are you going to make the fixture so that the dial gauge can be zeroed at radius of the rectified diff housing? (Apparatus 2044T page 35 of the illustrations)
 
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DoubleChevron

Real cars have hydraulics
Yes it is a time consuming process! Good to have a dial gauge, but also good to double check with the feelers as well!
How are you going to make the fixture so that the dial gauge can be zeroed at radius of the rectified diff housing? (Apparatus 2044T page 35 of the illustrations)
I'll sort that out when I get to it! I thought the pinion depth would be set with the feeler gauges and the "side to side" mesh of the gears set with a dial gauge (I didn't realise you could do it with a feeler gauge).
 

gerrypro

1000+ Posts
I'll sort that out when I get to it! I thought the pinion depth would be set with the feeler gauges and the "side to side" mesh of the gears set with a dial gauge (I didn't realise you could do it with a feeler gauge).
All you need is a fixed pointer on the tooth flank. Then use feelers to measure the tangential clearance against the pointer! Take measurements every 90 degrees! Better and more easily done with a dial gauge!
 

DoubleChevron

Real cars have hydraulics
Hi Gerry,

did you say don't refit the locking tabs on both shafts, or just the top one? To get the pinion depth etc right ... I've just tightened them up but not torqued or retained them in any way.

finally the bottom shaft is done, now to fit up the reverse/1st idler and clean/check/refit the primary shaft. I'll have to read the manual again, but I haven't found the tightening torque for the two big shaft nuts yet!

seeya
Shane L.
 

gerrypro

1000+ Posts
Loctite does a better job! I would throw both the loctab washers in the bin! Book says 108.5 Ft/lbs Page 55 section 24 paragraph 'c'. I would go a little tighter,120 ft/lbs is more than adequate. Check the CW&P mesh again once the front nut is tightened and the bearing cap is tightend down! It can all change and you may need to modify your shim stack!
Cheers Gerry
 
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DoubleChevron

Real cars have hydraulics
Loctite does a better job! I would throw both the loctab washers in the bin!
120 foot/lbs is more than adequate. Check the CW&P mesh again once the front nut is tightened and the bearing cap is tightend down! It can all change and you may need to modify your shim stack!
Cheers Gerry
I rattled the lower shaft down down with a small battery rattle gun to make sure everything was tight before measuring. This was my concern about tightness of the lower nut. If I rattle it down (which is probably only half the torque it needs to be) ..... the floating gear binds up. I'm guessing everything will settle down and it'll free itself once the gearbox has loads applied to it.

Oh, the replacement reverse idler gear ... when I was cleaning it I found the square shaped hole behind the bush.... The replacement gear was full of muck and metal and 100% blocked end to end (I needed a length of wire to push out all the debris)..... the failure mode of all of these gearboxes must be broken bits and metal circulating :eek:
 

gerrypro

1000+ Posts
Hint:- When adjusting the running load on the tapered roller bearings of the diff set the adjusting rings tight so that the correct back lash is 0.19mm and that the diff unit is a little stiff to turn on its bearing. Then open up the adjusting ring on the crown wheel no more than a couple of slots on the ring to give the correct freedom of movement. Then check the back lash again. If it has gone too loose tighten the ring a notch and back off the ring on the opposing side! Then the caps can be tightened and split pins inserted!
 

gerrypro

1000+ Posts
If the floating gear binds up you will need to select a thinner celeron washer to give the running clearance. Did you do a full assembly of the pinion shaft on the bench first with everything tightened up to spec in order to check the running clearances of the floating gear?Oh and is the roller race fully fitted?
Page 53 section 20 Paragraph 'a'!
 
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gerrypro

1000+ Posts
This was my concern about tightness of the lower nut. If I rattle it down (which is probably only half the torque it needs to be) ..... the floating gear binds up. I'm guessing everything will settle down and it'll free itself once the gearbox has loads applied to it.
No Way! Get it all smooth and turning freely before you install the box!
I told you these things are fiddly, and full of traps!
 
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DoubleChevron

Real cars have hydraulics
You will get there! I have every confidence!
If something is worth doing .... Its worth doing 101 times :) .... I have the clearance at about 0.16mm .... It closed up a LOT with the shaft nut tightened down (so the C washers certainly do not supply the crush against the celeron washer, the entire shaft pulls down against it with the end nut). Weirdly the pinion depth is so close still... its not worth touching (slightly loose rather than slighty tight drag against 1.7mm feeler gauge).

I'm glad I whipped up to bunnings and grabbed a much larger feeler gauge set. It helps a LOT not having to stack a lot of gauges to get the right reading (who would have thought, bunnings of all places is where to go for a larger feeler gauge set).


The reverse idler shaft still has slop, but less with the washers reversed.

I've just tried to make sure I've got all the metal particles out of all the parts before I assemble the primary shaft. How on earth was this car still driving with all that metal circulating in its oil.

This is a much more fun challenge when you throw all the bits into boxes, move them around the shed 1/2 dozen times over 2+ years. Have the gearbox pulled out by someone else and partially dismantled at a different location by someone else... ..... Then 2.5years later pull out boxes of completely foreign looking parts and try to work out the order they go back together in. Especially the different washers on the primary shaft, none of the manual diagrams are clear enough to identify exactly what goes where.... I'll refer back to my photos earlier in this thread (gee's I'm glad I took them!)

Fortunately I've found the top cover, front covers and missing bits in a box in my fathers shed (well hidden under the nose of the 2cv carefully placed among DS parts). This is my trick too.... Pull apart 1/2dozen completely different cars and mix all the bits together in the same shed, just to give yourself a challenge a few years down the track :ROFLMAO:

seeya
Shane L.
 

gerrypro

1000+ Posts
The C washers provide the lock up between the front race, 3rd gear speedo worm drive and 2nd gear. If it is putting thrust against the celeron washer, the floating 1st/rev. gear and the thrust bearings then it is not doing its job to provide a secure fore aft fixing for the pinion shaft. The floating gear must rotate freely when all is torqued up.
An old trick when new C washers were not available was to grind the worn C washers down until flat. This meant the Celeron washer had to be thinned also as the splined gear assembly( 3rd, 2nd, etc.) would be moved backwards by the amount that had to be ground off the C washers. Thank you European Parts Purveyors that new washers are now available!
Check that the 1.7mm is still there when the front bearing cap is tightened up and the shim stack is sealed. It may close down to the 1.6mm that you require!
 

DoubleChevron

Real cars have hydraulics
The C washers provide the lock up between the front race, 3rd gear speedo worm drive and 2nd gear. If it is putting thrust against the celeron washer, the floating 1st/rev. gear and the thrust bearings then it is not doing its job to provide a secure fore aft fixing for the pinion shaft. The floating gear must rotate freely when all is torqued up.
An old trick when new C washers were not available was to grind the worn C washers down until flat. This meant the Celeron washer had to be thinned also as the splined gear assembly( 3rd, 2nd, etc.) would be moved backwards by the amount that had to be ground off the C washers. Thank you European Parts Purveyors that new washers are now available!
Check that the 1.7mm is still there when the front bearing cap is tightened up and the shim stack is sealed. It may close down to the 1.6mm that you require!
I think I want 1.7mm for pinion depth!

20200802_104603.jpg


Its all rolling over very smoothly now and seems to measure right.

20200802_104330.jpg


Weirdly I've found third gear bush doesn't have the oil feed holes drilled properly. The 3rd hole doesn't line up (I'm thinking I should just drill it out!). It must have been like this from the factory. I'm also guessing it doesn't matter which side of the synchro hub spline the key goes into (it can key into 2 different places).

seeya,
Shane L.
 

DoubleChevron

Real cars have hydraulics
Well that has stopped progress dead ......

How can a 29.8mm bush possibly fit onto a 30mm shaft..... Unfortunately I cut up the old bush to make the spacer between them with. I guess I try to buy another pair of bushes, as there is no way this will ever fit onto that shaft! I might press them back out and see how they measure when not squeezed into the gear.

I should have known not to buy new parts (they are always no good in my experience ... especially if made of rubber!).

seeya,
Shane L
20200802_120351.jpg
 

gerrypro

1000+ Posts
I have some spare original bushes. I am guessing that the suppliers expect that you will grind the shaft to suit, or that your shaft will be worn!
It looks like you are doing a very good job!
 

DoubleChevron

Real cars have hydraulics
Actually the book says that the bushes must be reamed to suit the shaft!
Page 52 section 17.
Oh wow ... So I'm machining them .... great. reamers would be better, but I don't have any. A worn shaft will not work as you first need to get the bush over quite a long length of unworn spline.
 

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