Hello all.  Back in August I replaced my differential yokes and snap-rings (old one on the drivers side was shorn off and yoke was hanging out).  After completing the job I had an alignment done and the within 15 miles it died.  The driveshaft spins but not the tires – work heated up so the car has sat until now. Saturday I am opening up the differential case to see what the deal is.  My driveshaft is over to the passenger side, I read that most C3’s are like this – but I thought I would mention it since perhaps its an alignment issue putting undue stress on the driverside yoke and that’s busting the snap ring.

 

At this point I think I am going to remove the rear and have it rebuilt – if I do can I install the rebuilt rear myself or is there a technical alignment that really needs a professional?  I mean, aside from the 4 wheel which I would need afterwards.  I was looking at parts online and assuming $200 in labor a rebuild could run me about $700.  Alternatively, Ecklers sells a rebuild for $1,000 – I am not concerned for the cost difference.  I am more concerned if I can treat a rebuild like plug and play plus a wheel alignment and be ok ?

 

Any thoughts? 

Crimson Ghost2010-11-05 03:50:56

The diff is mounted solidly to the rear crossmember...ain't really but one way for it to go, so there's no alignment issues with the remove/install.
And yes...all Corvettes(and most other cars too) have the engine/trans off-set to the passenger side slightly. This has more to do with the clearance needed for the steering gear than anything.
Is the diff making any noise since it won't move? Was it making any noise before? The only things in the diff that would keep the car from moving would definitely make noise if broken/failed. If it is a posi unit, you could have one of the yokes stripped, but it should still move the car, unless the posi clutches were wiped out.
This is a strange one...
Go ahead and save the $$$ on the labor to remove/install the diff, and do that yourself. There's really nothing you could mess up by doing it yourself, except maybe leave a bolt out or something. There is no alignment issues with it. It simply bolts solidly to the crossmember, and then you have the front "nose" mount that attaches the diff thru a cushion to the frame.

Hello Joel, thank you for the response – I really appreciate it.  You confirmed my suspicion, when I replaced the yokes it certainly appeared to be a bolt on.

 

My yokes had too much play in them, after I installed the snap rings I could pull them out about a ¼ inch.  I have since read that the allowance is something like .0005 I was way over this.  I suspect this is the issue.

 

There was a clunk (a few actually) and I could tell something was wrong, but I tried to get home – no luck there.  It just died, no more go – yet no noise.  I jacked it up and ran it, the driveshaft spins, the passenger tire spins in the air and the driver side tire just sits there.  But there is no noise at all?  So I am at a loss.  

Sounds like the clutch pack has fried as well as the gear the yoke splines to on the inside of the diff..if you have posi..I would take it out and see what actually is broken..I have seen these rebuilt rears in Ecklers and Mid America..you can choose the gear ratio and posi..send in the old and get a rebuilt in the mail..only thing to think about is if the rear has a VIN or other number on it that says it came with the car..if you want to keep it original then have the one in the car rebuilt locally..or send it to Joel! I am sure he has done plenty of them..
Rich

The real question is why did it happen.  

 

The yoke was hanging out on the drivers side about 2 inches when the car was lifted.  So I opened it up, replaced both yokes and snap rings.  Put it back together and drove it a few miles – had a 4 wheel alignment done and it clunked right after the alignment and was broken within a few miles.

 

I am fearful that there is something else causing the issue.  I don’t want to spend $1,000 and have it break again – this is why I asked about alignment.  Right now I understand that the differential assembly can only be installed one way and no alignment is done out side of the case.  I am going to remove it today and have it rebuilt locally – will probably order the parts from Ecklers and then just have the labor to contend with.  I am certain I will be back to ask you all what I need to order.  I think this is a 3:70, later today I will count teeth and then get back to you all.

 

I started another thread asking for advice on removing this – I was uncertain how to go about the strut’s.

If it didn't make any noise on the way to get a 4WA then maybe I mean maybe when they adjusted for camber it moved the top of the wheel out which would pull the axle out a little and make a weak part in the rear stress and fail faster than what it would have..it would have failed regardless as you said endplay was over a 1/4 of an inch.
Rich

[QUOTE=yostusota]If it didn't make any noise on the way to get a 4WA then maybe I mean maybe when they adjusted for camber it moved the top of the wheel out which would pull the axle out a little and make a weak part in the rear stress and fail faster than what it would have..it would have failed regardless as you said endplay was over a 1/4 of an inch.
Rich [/QUOTE]

Any opinion on this:

Oh well no big deal..I guess the causal part of failure was the diff..I would say that anything drive train related should have very little end play..check your rear wheel bearings also..you really shouldn't feel them move and need a dial indicator to see how good they are..if they are good get the packing tool from Mid America..I don't know if Ecklers has it..since you have the shafts out it only takes a few minutes to grease them..
Rich

Oh, I am new to everything - I bought this car to learn on.  I don't know how to check the wheel bearings :-)