Finally ... Repairing a traction gearbox.

How would we do all of this if I couldn't drive Gerry crazy with a million and one questions :)

20200723_222505.jpg


Is there anything at all I can just do without asking questions.....

20200724_223143.jpg


20200724_223200.jpg


So it looks really simple, you just measure the satelite gears are less than 0.5mm above or below the planet wheel.....

20200724_223101.jpg


Yeah right .... How the hell do I measure down in there where I can't access....

20200724_223313.jpg


Or even worse, when I bolt the crown wheel back on ... how on earth do I measure inside a fully enclosed diff housing ?

seeya,
Shane L.
 
Simple! Just sit the loose sun gear and shaft on top of the satellites with out the crown wheel and measure the amount of protrusion above the periphery of the gear. To establish the thickness of the 'Celeron' washer place it on the shaft as above and use a straight edge across the diff top hat housing. you should be able to get about .05mm feeler gauge in between the straight edge and the washer! This should prevent binding. If the gear sits too high then the thickness of the 'Celeron' washer behind the sun gear already fitted into the Top Hat will need reducing, and the domed washers behind the satellites will need increasing. This is in an ideal world where bits would be readily available. You can probably be OK with slight adjustments of the 'Celeron' washers if the assembly is binding as it is turned.
The two short shafts look a little suss! but the long shaft is probably OK.
Did you find better satellites? They appear to be better than the ones in the original photos! Or is it just the way you took the pic?
 
Last edited:
Thanks Gerry,

they all show heavy wear marks and ovalizing. Everything within the diff is heavily worn. Which is strange as the rest of the gearbox wasn't really worn (it was damaged). There is no bearings or bushing in the diff satelites, so I'm not sure how heavy wear can be avoided. Replacement would be the only option. Is there sufficient lubrication in the diff ? It appears oil can only flow into the satelites if the celeron washers are fitted in the correct direction (so the oil path pressed into them) allows oil flow.

its all quite interesting the way this was designed and built.

seeya
Shane L.
 
gerrypro said:
Simple! Just sit the loose sun gear and shaft on top of the satellites with out the crown wheel and measure the amount of protrusion above the periphery of the gear. To establish the thickness of the 'Celeron' washer place it on the shaft as above and use a straight edge across the diff top hat housing. you should be able to get about .05mm feeler gauge in between the straight edge and the washer! This should prevent binding. If the gear sits too high then the thickness of the 'Celeron' washer behind the sun gear already fitted into the Top Hat will need reducing, and the domed washers behind the satellites will need increasing. This is in an ideal world where bits would be readily available. You can probably be OK with slight adjustments of the 'Celeron' washers if the assembly is binding as it is turned.
The two short shafts look a little suss! but the long shaft is probably OK.
Did you find better satellites? They appear to be better than the ones in the original photos! Or is it just the way you took the pic?
Click to expand...
Your explanation makes far more sense. The figure 4 refered to in the manual is nonsense. You can't access the area in question to measure what the diagram shows (and what is shows would be set by the planetary gear washers more than celeron washer.

Now setting to put 0.5 this measurement would make sense. I'm about 1mm under.

20200725_143900.jpg



just pushing the pinion wheel up from below will show the slop. but this isn't what diagram 4 shows to measure.
 
The first picture in Fig 4 shows the mesh under engaged. The second picture is over meshed. The trick is to balance out the mesh changing the washers. Your dome washers look comparatively unworn often they are so bad that you cannot see much of the eccentric oil groove anymore.
One tip is that you can reduce the thickness of the Fibre washer( Celeron) by lapping down with wet and dry on a sheet of flat glass. If you are at 1mm. under meshed then the fibre washer needs to be increased in thickness. You need a selection of washers from which to choose a thicker example. Even if it is too thick you can use the above procedure to reduce the thickness until it is right. This may bring the dome washers back to a correct setting or they too may be too thin to stop the satellite being pushed up and down ( rattling noise ). Then it is possible to turn up some washers to insert and make up the slack. This method also involves a lot of lapping down and fitting.
 
gerrypro said:
The first picture in Fig 4 shows the mesh under engaged. The second picture is over meshed. The trick is to balance out the mesh changing the washers. Your dome washers look comparatively unworn often they are so bad that you cannot see much of the eccentric oil groove anymore.
One tip is that you can reduce the thickness of the Fibre washer( Celeron) by lapping down with wet and dry on a sheet of flat glass. If you are at 1mm. under meshed then the fibre washer needs to be increased in thickness. You need a selection of washers from which to choose a thicker example. Even if it is too thick you can use the above procedure to reduce the thickness until it is right. This may bring the dome washers back to a correct setting or they too may be too thin to stop the satellite being pushed up and down ( rattling noise ). Then it is possible to turn up some washers to insert and make up the slack. This method also involves a lot of lapping down and fitting.
Click to expand...
The up/down crownwheel is 1.4.... So wouldn't the celeron washer need to be increased by 0.9 to bring the mesh down to about 0.5mm :confused: Both celeron washers are about 0.8/9 to thin (unless I'm measuring this incorrectly).

I can't do anything about the dome washers, they have wear marks. I'd need a packet variety of sized washers to shim it correctly . Look at that you can buy them .... https://www.citroen-traction-avant...._Cod/VERSNELLINGSBAK-DIFFERENTIEEL/PageSize/0 If you were wealthy you could replace nearly everything worn with new!
 
Do you have a number of Celeron washers available that will fit the diff shaft? I have been known to take two really thin ones and glue them together. Then they can be lapped back to size!
Yes the bits are available new.
I'll check out what I have available!
 
gerrypro said:
Do you have a number of Celeron washers available that will fit the diff shaft? I have been known to take two really thin ones and glue them together. Then they can be lapped back to size!
Yes the bits are available new.
I'll check out what I have available!
Click to expand...

Hi Gerry, its interesting. I've gone through all of your diff celeron washers ..... all are 1.9 to 2.0 ... So the only option is to glue two together and sanding them down. I wonder if the factory just assembled the diffs with ~2.0 washers and called it close enough :). I hadn't noticed before, there is a variety of 3 different sized celeron washers (different sizes, as opposed to thickness).

seeya,
Shane L.
 
DoubleChevron said:
Hi Gerry, its interesting. I've gone through all of your diff celeron washers ..... all are 1.9 to 2.0 ... So the only option is to glue two together and sanding them down. I wonder if the factory just assembled the diffs with ~2.0 washers and called it close enough :). I hadn't noticed before, there is a variety of 3 different sized celeron washers (different sizes, as opposed to thickness).

seeya,
Shane L.
Click to expand...
Some of those are also for the 1st/2nd/Reverse cluster gear on the pinion shaft and also for the 2nd/reverse synchro gear. The diff celeron washer will have a chamfer on the inner diameter. This chamfer must face the back of the sun gear.
I had forgotten that I let you have a selection of those washers. I had a look for more spares and couldn't find any! Now I know where they are! (ha-ha)
 
gerrypro said:
Have a look here! https://www.cas-shop.com/en/product-categorie/gearbox-differential/
Click to expand...

Wow ... some of the used parts he's selling look worse than I have here :) ... Another interesting thing I noticed was the diff bearings. The race is made in sweden, but the bearing itself is made in france.

I've decided I need to write down anything I lend out (so wherever they live in the shed, put something there with "lent to xxxxx" on it).. I've lost quite a few tools over the years, simply because I can't remember who I lent them too. I can't remember who I lent the laptop and lexia stuff to either. I haven't seen it in a few years. I have you diff adjustment and synchro hub tools here.

seeya,
Shane L.
 
  • Like
Reactions: cjl
Yes and also the stack of pinion setting shims! I remembered that much. I loaned out the drive shaft ball and spigot extractor a while ago and found recently that only on set of collets came back with the unit. I can't remember who it was that borrowed them. So now I only loan out things to special people and on very rare occasions!
 
  • Like
Reactions: cjl
DoubleChevron said:
Wow ... some of the used parts he's selling look worse than I have here :) ... Another interesting thing I noticed was the diff bearings. The race is made in sweden, but the bearing itself is made in france.
seeya,
Shane L.
Click to expand...
Some of those pieces are new old stock but will clean up well enough to use. I was more interested in the range of shims and thrust washers.
PS Barry Reikers at CAS is really helpful. He was the original owner of CTA Nl. I recently bought pulley and brushes for the 6 volt dynamo. They arrived in 2 weeks from the payment date. Not bad considering the current world situation!
 
Who watches the jay leno stuff on youtube .... a couple of months ago a traction appeared in the background .... and now this

leno.jpg


2cv hoffman right ?

anyway, its always best before you buy parts to not check *everything*.

20200725_161637.jpg
A

A smart person would have purchased some new studs back when they ordered parts ... sigh....

20200725_152715.jpg


Anyway, I found it you put a few bolts into the pinion gear ... it'll pull down about 0.2mm closing up you tolerances.

20200726_114223.jpg



Wow... I have these lovely manicured nails now .... and my fingertips look to have no fingerprints left ....

There is a high spot as the meshed teeth roll over. 0.5mm must be pretty much the exact meshing clearance required. crown wheel side needed to be set to about 0.75 to prevent binding and the other side slightly over 0.5.

20200725_161321.jpg


The orginal diff seals are contained in a metal housing! Maybe they used to get damaged on the roads that were around 90years ago?
 
The best meshing clearance according to fig.4 is 0.0mm That is exactly level with the mating gear. The 0.05mm is the plus or minus tolerance.
If you close the meshing to the new specs the amount of wear will cause high and low spots and therefore you fell some binding as the diff is turned. This should smooth out with use if it is not too severe.
 
gerrypro said:
Do you need some of these?
View attachment 123836
Click to expand...

That's funny, you have that many spares? I've run an M10 x 1.5 die over them. They should probably hold up (given they were in a driving car in the mangled condition they were in). I'm guessing I'll find out where I torque the shafts down ( so about August .... 2037 :rolleyes: ) ...

with the speedy sleeves, 'll take them upto the bearing place and see what they say .... "Probably ... urgghh.... metric .... " :ROFLMAO:

It's only taken 2.5years .... But I have assembled one part now .... the diff is back together and ready to fit. I think I'd finished all the clearances in the pinion shaft ( 2.5years ago), so in theory I can slide that in and set the pinion depth.

I've got a cheap dial gauge coming in the mail .... so hopefully I can button up the bottom half of the gearbox this week.... Then its onto setting the clearances in the top shaft.
 
The lower shaft sure is lovely and snug around the celeron washer .... I assembled it on the bench in 5seconds without any problems at all....... Er, would you believe "challenging" describes trying to install those "C" washers with it nice and snug.... I'm glad I have a magnet hand for retrieving them from the bottom of the box ..... many times :)

seeya,
Shane L.
 
You must log in or register to reply here.
Top