GiSelle the GS Mechanical Refresh Mark 2

David S. The bearing you have indeed appears to be the rear bearing for the pinion shaft. The number doesn't match that in the parts book, but they rarely do in my experience.

Young Ken, the input shaft rear bearing appears to be SKF 445195D.

The drive shaft flange bearings are standard 6205 jobbies, same as on the 2CV!

More information once I collate it all into the next marathon post!

Cheers, Pottsy.
 
David S: Looking up the SKF number I mentioned above seems to result in a totally different bearing, so I need to double check what I read off that particular bearing.

In the meantime, I've discovered a couple of things, both good and bad.

Numbers in brackets refer to the drawings attached below, just in case you thought I was encoding a secret message!

Murphy's Law just never gives up!

First issue is the output shaft bearings. (See photo from Manual 810-2). These are the ones held in the sides of the gearbox by a threaded collar (1) and which support the drive flange axle on one side and spline into the diff on the other.

On the up side, the design is exactly the same as on the 2CV and the good news is that the bearing is also the same one as on the 2CV, a 6205RS. This is a fairly standard bearing which I've sourced in Oz once before. Great sez I, let's get a couple of the old ones off ready to replace them once I can whip out and buy a couple of newies. Ha!

On the down side, I've yet to manage to dismount the bearing from the shaft. I've got 6 of these pesky critters and only one has a bearing that sounds anywhere near quiet. So I look up the book. I quote (from the factory manual) "Use a universal extractor bearing underneath the ring nut as close as possible to the shaft."

The space available between the ring nut and the flange is about 3.5mm or so. I've got split type bearing extractors and they don't quite fit in there. When I did manage to persuade one to get a grip in there I can't make the bearing and or the sealing ring (3) budge at all. I've tried heating the seal ring with a gas torch but so far no joy. It looks like I'll have to break out the weldy machine and an angle grinder and cobble up a bespoke puller assembly.

OK, take a deep breath and move on to a different task. I needed to remove the speedo drive nut (8) off the end of the pinion shaft in order to access the 3rd and 4th gears to replace the 3rd gear synchro assembly. The speedo drive nut is a 36mm. I remember buying one of those years ago as it's the size of the crankshaft pulley nut on the front of a 504 Pug. Can I find it? Of course not. It turned out No 2 son had it and delivered it when he went out shopping. Phew!

So on to the two large bearings on the rear of input shaft (30) and pinion shaft. (28) These are hulking big double row ball bearings. At Last a WIN! Both of these appear to be in beautiful condition so I'm happy to re-use them. The front bearing on the input shaft (32) is a roller cage and it also appears OK so far.

For edification and delight I've done a hand drawn photo (sketch to you Smithers!) of these two big bearings. One has an SKF number on it but as mentioned above I'm a bit suss on whether I've read it right, as SKF seem to think it's a totally different thingy from their website.

So there we have today's progress. Next task is to remove an innocent looking circlip (19) without scratching the pinion shaft surface. Another Challenge!

Onwards and Upwards Folks!


The Triffids gathered together and took a vote on who was to confront the family cat in regard to property rights. The Chosen One is yet to return, but the cat looks happy!
 

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The bearing I have is your #28, but you won't need it as you have declared yours OK.
What is the OD of your 3rd gear and the number of teeth. I have a cog and synchro ring that looks very similar. 80mm OD 33mm ID 32 teeth. I'm not sure if it's GS though. Or are you saying you have a good used item to use?
 
Hi David. I'll check the dimensions of the gear first chance.

I'm trying to make the minimum of changes to avoid having to reset the crown wheel back lash. If I don't change the bearing or any of the gears it all should be the same settings and the existing shim (2) should suffice.

I'll measure the base diameter of the cone on the gear, however, and if it's less than the spare gear I have I'll bite that particular bullet and use it. I'm hoping that since the spare ring I have results in a clearance of about 20+ thou whereas the one that's in there has close to zero thou I can simply replace that and move on.

As a comparison I'll measure the cone to ring clearances of the other gears, which are synchronising fine, and see how it looks.

Cheers, Pottsy
 
Hi David. I'll check the dimensions of the gear first chance.

I'm trying to make the minimum of changes to avoid having to reset the crown wheel back lash. If I don't change the bearing or any of the gears it all should be the same settings and the existing shim (2) should suffice.

I'll measure the base diameter of the cone on the gear, however, and if it's less than the spare gear I have I'll bite that particular bullet and use it. I'm hoping that since the spare ring I have results in a clearance of about 20+ thou whereas the one that's in there has close to zero thou I can simply replace that and move on.

As a comparison I'll measure the cone to ring clearances of the other gears, which are synchronising fine, and see how it looks.

Cheers, Pottsy
Did you measure the backlash before disassembly?
As the diff support bearings wear the backlash increases. Don't assume that the original bits are still giving correct adjustment.
You really need to reset the backlash.
 
Bob, no, I'm ashamed to admit I didn't.

"By the Book" if the side bearings of the diff and the pinion shaft and end bearing (and spacer) are not replaced, it should be unchanged but I take your point that wear happens. The lazy part of me was trying (hoping) to avoid sorting out diff bearing shims etc, but if I have to do it I will. In an ideal world, once I reassemble with the original pinion shaft spacer shim and bearing the backlash should be inside tolerance, but I won't know until I'm at the reassembly stage anyway.

Time will tell. I'm not rushing this job. Getting into the nitty gritty of such engineering is a pleasure.

David S, I've measured the spare gears I have.

The 3rd gear is 32 teeth and the overall diameter is 80.89mm, gear width 14.25mm.. The diameter of the cone part at the root, ie, the base of the cone, is 49.04mm.

The 4th gear is 28 teeth and the overall diameter is 71.49mm, gear width 16.18mm. The cone root is 48.80.

I believe the cone root dimension is going to be critical to whether the synchro rings do their job properly, but yet to remove the gears from the complete gearbox to find out.

My understanding is that the greater the clearance between the face of the gear at the root of the cone and the face of the ring, the better the synchronisation. From what I can tell so far the existing 3rd gear clearance is 5/8 of bugger all, but I've yet to remove the gears. I'll do some sketches at some stage, less for elucidation than for my own clarity of understanding.

Cheers, Pottsy.

The cheering crowds urged the intrepid climbers on as they tackled the precipice before them. It was only when the first one fell that they realised they were all underneath! (Too dark perhaps? :) )
 
The 3rd gear is 32 teeth and the overall diameter is 80.89mm, gear width 14.25mm.. The diameter of the cone part at the root, ie, the base of the cone, is 49.04mm.

Essentially the same dimensions as the cog I have loose here. It has signs of use, so is obviously used. The cone has what appears to be a rubberised coating and the synchro ring sits slightly proud of the gear when fitted. Three tangs on the ring to slip into the synchro hub. If you need it, send a pm.

There is a set of checking 'gauges' to set up various gearbox clearances and a wide assortment of shims in the parts list. CCCNSW has custody of this gauge set and also the factory tool kit to fit the engine oil seals.
 
OK, here's the definitive info on synchro rings I've found.

First of all, the 3rd gear ring was sitting flush with the surface on the gear. An undesirable situation.
The ring is quite worn inside resulting in zero clearance.
A "good" ring on the original gear sits proud by around 30 thou, so will(should) provide "synchronising friction" when asked to do so.
The photo of worn and good rings together is pretty telling I reckon.

So, once I make a special tool to hold the retarding dowels while I put the 3rd gear back on, I can proceed to re-assemble with a degree of confidence that the gears will work proper like.

A quick check of the other clearances shows them to be between 20 and 30 thou. None of them are as worn as the 3rd gear one, which is encouraging.

These pics should tell the story I reckon.

Onwards and Upwards Folks! Pottsy.
 

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OK, here's the definitive info on synchro rings I've found.

First of all, the 3rd gear ring was sitting flush with the surface on the gear. An undesirable situation.
The ring is quite worn inside resulting in zero clearance.
A "good" ring on the original gear sits proud by around 30 thou, so will(should) provide "synchronising friction" when asked to do so.
The photo of worn and good rings together is pretty telling I reckon.

So, once I make a special tool to hold the retarding dowels while I put the 3rd gear back on, I can proceed to re-assemble with a degree of confidence that the gears will work proper like.

A quick check of the other clearances shows them to be between 20 and 30 thou. None of them are as worn as the 3rd gear one, which is encouraging.

These pics should tell the story I reckon.

Onwards and Upwards Folks! Pottsy.
Excellent, its the synchro that has worn. I reckon its the gear that wears more in CX's than the synchro. So it gets to the point where new synchros make little to no difference as the gear itself is worn :(
 
Excellent description of the wear, Pottsy. Re Bob's entreaty that you do the diff lash, if you do get to have to do that a simillaly detailed commentary on that process will be invaluable to us all. Cheers. Ian
 
Ian, your wish is my command O Wise One :)

I've just finished adjusting the assembly. The photos show the sequence I think. Having a cuppa.

The shim (2) that was originally fitted resulted in a reading of about 0.35mm. Spec from manual 810-2 is 0.13 to 0.27mm so I looked around for a suitable shim to add to the original. Blow me down with a pinion if the shims used to adjust ball joints in a Mini aren't as close as one could hope for!

The inside diameter is larger, but not enough to interfere with any of the bearings bits, and once it's all torqued up of movement there should be none. The "real one" is uppermost in the pic with the Mini one below.

I tried a 20 thou one first of all, but that was too much so I've settled for a 12 thou shim and you can see the results below.

I didn't want to faff about with the bolts at this stage of pre-assembly so I used vice grips to hold the halves together. A bit of cunning bracketry sort of replicated special tool 3184-T to position the dial gauge. I know I've mixed my metrics again, but since the spec is given in mm I thought I'd use the metric gauge, even though I've selected an imperial shim. (Braces oneself for Anglo-French conflict! :) )

So with the shim inserted, the halves clamped up, the end nut nipped up and the end cover on and also nipped, the result was just under 0.2mm, which I think is acceptable. There's no perceptible movement in any of the diff components or other bearings, so I reckon I can button it up after a good cleaning.

So here are the pics in order,

Cheers, Pottsy
 

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OK, I'm just about bozforricked with these bloody things!

I called them pesky critters before, I'm now of a mind to upgrade them to recalcitrant bastards!

I'm referring to the output shaft jiggers. (See first pic). Mine are all type B which have the seal ring (3) and bearing pressed on to the shaft. What I'd give for type A (threaded assembly) at the moment!

After trying my large split bearings remover under the whole "cover, bearing & seal ring" assembly, and the puller starting to bend, I thought I'd have a go at removing the sealing ring on its own with the smaller bearing remover.

Yep, you guessed it. Bent!

So it was onwards and upwards. Break out the angle grinders and the weldy machine and have a fossick through the bits piles.

What I ended up with is not pretty, and please ignore the look of my out of practice welds, but it seemed to do what I designed it for.

The bottom plate is of a thickness to slide under the assembly, with cutouts to allow full insertion so it's all snuggling up tight to the threaded collar face. A couple of lugs each side to stop it kicking outwards once wrapped around. Four length of M8 all thread and a spacer plate. A centre bit from an old three leg puller. The plates are 75mm square post washers about 4mm thick. The bit of round was something I had lying around.

Once it was all jigged up and welded together, the spinny cutty thing was used to bisect it.

So on it went to one of the aforementioned pesky critters.

My heart was full and expectations high as I gradually applied rotational force expecting to see things come loose and slide off the shaft. Hah!

So I broke out the gas torch and filled the shed with smoke while increasing the thermal content of the things to a level called "ouch".

The central bolt was tightened until it would tighten no more. I have a tool that I call the "Spin up and Bang" device which is a rotary tool with a centrifugal hammer inside. When it gets up to a lot of revs, the hammer spins out and applies a smack to the socket shaft. This thing has yet to fail me. Until now.

And the result? Nothing broke, but it all started to bend, and still the ring and bearing sit there taunting me!

My tether is under extreme tension by now!

Anyone got any ideas? I've used a large amount of WD40, lots of heat, torsional forces high enough to kick start a Mack, and all to no avail so far.

Looking for the Brains Trust to help me here! Anyone got a magic wand? :)

Grumps, Pottsy.
 

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Pottsy,

I presume you are following the factory manual here? There might be a thread involved holding the collar on.

Cheers, Ken
Gearbox output shaft disassembly.JPG
 
Hi Pottsy. I feel your pain. It's a bugger when you work so hard and don't get the desired result. While I haven't done this particular fitting on a GS, whenever I have tried to remove a bearing which is secured by a pressed on collar I have drilled into the collar and then broken it with a the cold chisel first, then allowing the press fit bearing to be removed. The collar always seems to be tighter than the bearing inner, probably because they are usually fitted hot so that the pressing and the combination of shrinkage give that tight fit. I take Ken's point that the diagram he sent refers to a thread, But it seems that the two examples in the picture are different and so a previous or alternative carrier might have had a nut but yours doesn't look it does. The problem with splitting the collar that way is that you then need a new one to replace it. The collars always come with Axle bearings, but they may be a separate purchase piece in this application. Ian
 
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Pottsy,

I presume you are following the factory manual here? There might be a thread involved holding the collar on.

Cheers, KenView attachment 135714
Yeah, I posted that same pic from 810-2 in posts 63 and 74. GiSelle has type B, the right hand one with the (presumably) pressed collar. If it was the left hand one held on by a nut I'd have it sorted by now. (The 2CV uses a type A design flange with the assembly held on by a nut.)

When it says "remove the bush" it sort of implies it should come off easily. If it was threaded on I would think there would be evidence of a thread where the bush meets the shaft, but there ain't. If I try to turn it, whatever tool I use is going to monster the face, which I've tried to avoid so far.

Note that the book says "use a universal extractor". Well I've tried several types and ways with no joy. That's right up there with Mr Haynes myth "reassembly is a reversal of removal!".

Ian. I've heated the collar a lot, using a couple of different propane torches, but maybe they're not focused enough. I was sort of hoping it may loosen up while I had the puller under tension, but no.

Once I re-weld the bespoke puller where the incredible forces have torn it (!) I'll break out the oxy set I guess and see where that gets me.

I'd be happy to destroy the bearing which would give me a clear shot at the collar, but the bearing is shrouded by the screw on cover so a difficult task. I really want at least two of the collars intact and usable.

Ah well, as pantless pollie once (allegedly) said, Life wasn't meant to be easy!

Thanks chaps, Pottsy.
 
I've just been doing a bit of searching through the parts books. It appears that the early cars had the threaded type of output shaft whereas the later ones had the recalcitrant bastards.

I just remembered I have what I think is an early complete engine and c-matic unit under a cover in the garden. (Beats a bloody gnome!)

It's got me wondering whether the box has the early unit, in which case I'll use then with new bearings and seals and consign the aforementioned RB's to the storage bins for the nonce.

According to the parts book, they even share the same part number and nombre de dents.

A job for the morrow methinks. 'Tis rapidly approaching Beer O'Clock.

As you were chaps, Pottsy.
 
Ok. I did this on my convertisseur gearbox. I have experienced all that you have. In the end I removed the collar first, then moved onto the bearing. I don't believe you will get to pull off both at once. Too much force. I also was trying to be careful and not bend the ring nut. Which thankfully I didn't do.

You have to work the puller into the gap / lack of gap between the bearing and the collar. As I tightened the puller horizontally a little at a time and vertically a little at a time I "belted" the puller with a soft face hammer. A bit more tightening, bit more percussion. It eventually came off. Lots of Penetrene. Tried heat but didn't help too much.

I think the manual actually suggests you have to cut the collar off and fit new ones. Bearing splitter? I did see that you could get new ones from overseas but I didn't want to wait. I didn't damage the old ones on removal, thankfully. But a painful process none the less. Good luck.

I nearly didn't do my ones but after I got the bearings off and felt them I was glad I did.
 
Thanks Garth. I feel a little encouraged.

As you'll see in post 74, the pic labelled "small puller" I tried getting the small splitter in behind, but it ended up slipping along the surface of the sealing ring.

I'll try dressing the bearing splitter with a flappy disc and see if I can match the curve to the seal ring a bit better. Also will try squeezing it in with the vise at the same time as pulling, if that makes sense.

Cheers, Pottsy
 
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