A New problem with the diff - HELLLP!!!
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
A New problem with the diff - HELLLP!!!
I have the diff down so replace the snap rings and Seals.
Was cleaning the inside when I noticed a possible problem.
It looks like there is a steel spacer between the carrier bearings and the side of the differential case. It looks like the spacer on the pass side is cracked.
I have no experience working on differentials. As I said above the work I was going to do was simple and did not require taking the carrier out.
What is this spacer called? Where do I get one? How hard is it to take the carrier out to 'just replace the cracked spacer'?
EVERYTHING else inside looks nice and clean.... no signs of wear. Besides the need to replace one of the snap rings, the diff was working great at the time that I took it down out of the car.... posi was just fine.
Was cleaning the inside when I noticed a possible problem.
It looks like there is a steel spacer between the carrier bearings and the side of the differential case. It looks like the spacer on the pass side is cracked.
I have no experience working on differentials. As I said above the work I was going to do was simple and did not require taking the carrier out.
What is this spacer called? Where do I get one? How hard is it to take the carrier out to 'just replace the cracked spacer'?
EVERYTHING else inside looks nice and clean.... no signs of wear. Besides the need to replace one of the snap rings, the diff was working great at the time that I took it down out of the car.... posi was just fine.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by wombvette
They are actually shims. They are used to set the bearing placement and preload. What you see may be two shims and you are seeing the line between them.
This appears to be a solid metal spacer that is between the side differential case and the bearing for the carrier. (One on each side).
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Ok figured out how to get a pic...
If you click on it it will be larger and you can see on the right side of the carrier bearing, there is some spacer and it is clearly cracked.
What is this spacer called? Where do I get one? How hard is it to take the carrier out to 'just replace the cracked spacer'?
Last edited by genuine1980; Nov 8, 2006 at 12:29 AM.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Yes the factory used thick shims of the correct size when they assembled them. I am sure that was easier than stacking a bunch of shims. I see what you are talking about. I am not sure that it is really a crack, maybe? I have seen them with marks like that before. Even if it is, I dont see how it is a problem though. That thing is wedged in there fairly tight and there is no where for it to go. I dont think that I would worry about it. If you replace it, you need to mic it and replace it with the same thickness of shims.
Last edited by wombvette; Nov 8, 2006 at 01:46 AM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Oh that is cracked. They use cast iron spacers from the factory of the correct size they needed. To replace it you would have to remove the carrier and mic up the broken spacer. get a shim kit and replace it with the correct number of shims. You would need the same thickness as the one big spacer. Not really a big deal. But now you have the carrier out I would replace the clutch pack. Welcome to the While your at it syndrome of owning a C3. What was going to be an easy job turns into a body off resto. 
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
Those are cast iron shims, ground to size at the factory. They are not reused during a rebuild because
1- They break.
2- The size changes during rebuild
They are under "load" as these preload the carrier bearings. You may get by if you change the exact size steel shims per side but I would run a pattern check before and after. The carrier should be under enough load that it will not slide out. You have to put a bax wrench on a ring gear bolt and turn the pinion until it walks out. Stamp the bearing caps L&R before so you return them to the same location.
1- They break.
2- The size changes during rebuild
They are under "load" as these preload the carrier bearings. You may get by if you change the exact size steel shims per side but I would run a pattern check before and after. The carrier should be under enough load that it will not slide out. You have to put a bax wrench on a ring gear bolt and turn the pinion until it walks out. Stamp the bearing caps L&R before so you return them to the same location.
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Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by gtr1999
Those are cast iron shims, ground to size at the factory. They are not reused during a rebuild because
1- They break.
2- The size changes during rebuild
They are under "load" as these preload the carrier bearings. You may get by if you change the exact size steel shims per side but I would run a pattern check before and after. The carrier should be under enough load that it will not slide out. You have to put a bax wrench on a ring gear bolt and turn the pinion until it walks out. Stamp the bearing caps L&R before so you return them to the same location.
1- They break.
2- The size changes during rebuild
They are under "load" as these preload the carrier bearings. You may get by if you change the exact size steel shims per side but I would run a pattern check before and after. The carrier should be under enough load that it will not slide out. You have to put a bax wrench on a ring gear bolt and turn the pinion until it walks out. Stamp the bearing caps L&R before so you return them to the same location.
Now I'm sure a lot of you are going to upset to what I'm going to say
But since it is indeed just a spacer, and since it is under a load and will not come out by itself...
I am going to stick to my original plan and just replace the snap rings and outer seals.
Like I said I have no idea how to rebuild the diff... clutch pack, bearings and all that. Aside from the yoke sliding ina and out because of a broken ring, the diff and the posi were in perfect working order when I removed it. After cleaning the inside of the case with brake cleaner, everything looked new, with no sign of wear (besides the cracked spacer).
Thanks again
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
I can't tell if that is a crack or not. They usually don't break unless someone tried to hammer them in while installing them back.
That is an early diff as it has the full radius bearing caps, the later caps have a tab cast into them. Does it have the little sq rear window or the large tear drop one?
Did you find the snap rings? Bair in your home state should have them.
That is an early diff as it has the full radius bearing caps, the later caps have a tab cast into them. Does it have the little sq rear window or the large tear drop one?
Did you find the snap rings? Bair in your home state should have them.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Originally Posted by gtr1999
I can't tell if that is a crack or not. They usually don't break unless someone tried to hammer them in while installing them back.
That is an early diff as it has the full radius bearing caps, the later caps have a tab cast into them. Does it have the little sq rear window or the large tear drop one?
Did you find the snap rings? Bair in your home state should have them.
That is an early diff as it has the full radius bearing caps, the later caps have a tab cast into them. Does it have the little sq rear window or the large tear drop one?
Did you find the snap rings? Bair in your home state should have them.
I don't know how to tell if it is an early one or not... I dont know what a bearing cap is, but it does have the little sq window in the back of the carrier.
Thanks again
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
The bearing caps are where the bolts go through to hold the carrier in the case. The small back window carriers were the early ones used up to mid '69? Look it over good, they tend to crack more then the later units. Look at the edges of each window for small cracks forming.