my rearend is makeing these clunking sounds especialy while cornering but only after hard driveing like after getting off the interstate. around town it is just fine.
I have had the the rearend rebuilt and replaced all the u-joints and the trans mount. any thoughts? it is not the exhaust. it is definatly in the drivetrain.

|UPDATED|8/8/2004 8:24:28 PM (AZT)|/UPDATED|

after a recent rear end rebuild you need to change the differential oil and posi fluid..

you can just add more posi fluid as a temporary fix but it will come back..

the oil you add after a fresh rebuild often gets broken down pretty quickly..

I had the exact same symptoms on my last vette.. the posi started sticking once the rear end warmed up..

I drained the oil.. (I cheated and drilled and tapped a drain plug.).. filled it up with fresh oil.. problem solved

Very common. I can't tell you how many times I changed fluid and put in the additive when I worked for Chevrolet. Not in just Corvettes. Anything with a posi. I have had mine on the highway twice for a brief time. Same thing. I will change my fluid before the next trip out.

|UPDATED|8/9/2004 8:48:18 AM (AZT)|/UPDATED|

Ken,

I'm currently in the middle of a rear end rebuild right now. A quick question for you.

How common is the spindle wear, and does one side wear out quicker than the other?

The right side spindle was worn down right to the snap ring. I had to tap it out with my #1 wrench to get it out. I know they wear over time, but is this excessive?

Thank you, oh mighty Zen Master, your loyal Grasshopper.

Alan
The original man from Nantuckett.

Ah yes Grasshopper. They do wear. Look at the suspension. See anything to keep the tires up right? The trailing arms hold front and aft, and up and down. The strut arm hold the bottom in or out. The only thing that holds the top in or out is the drive shafts, and the stub (spindle) shafts. So wear is quite a factor.
As for the right wearing quicker, not uncommon due to applied stress. With crowned roads, there is usually more pressure on the right side. Just depends on where you drive.

|UPDATED|8/10/2004 6:42:29 AM (AZT)|/UPDATED|

While we're on the subject, Zen Master Ken, I've looked everywhere in my shop manual but can't find any spec as to end play on the diff drive yokes.

I would hazard a guess to say that as long as the snap rings are good it's not a problem as the loads on the yoke always push into the diff, therefore no pressure on the snap rings.

Both yokes have similar end play and the diff is in good condition, I'd just like to have a warm and fuzzy while I have the drive shafts out.

The snap rings hold the shafts from going outward. The end of the shaft keeps it from going in. The snap rings could be good, and the ends worn, and have too much play. Useing different thickness snap rings can adjust end play.

I just checked the specs through Alldata online. The oldest shown was 1982. Endplay is .0005 to .0085

|UPDATED|8/10/2004 8:29:54 PM (AZT)|/UPDATED|

thanks Ken, I knew you'd have the answer somewhere close at hand.

I've got the back end apart at the moment and the passenger wheel bearings are shot but the drivers side are good. Going to replace both anyway. Should get rid of my brake pedal pumping. All uni's are good so now all I have to do is rebuild my Gearbox (M20) and all is good.

Ken/Ben, my diff isn't giving me any trouble but I'm wondering if I should add some additive, without draining it. I have no idea whats in there or how long it's been there. It looks like a b**ch of a job to drain as no drain plug.

BTW Ben, where on the diff are the code letters for the gear ratio. Book says mine should be 3.36, but can't find any letters on the casing.

Thanks.

Just adding the posi additive into the present fluid won't hurt anything. It can only help. Unless you add way too much. But you could add it two or three times over the years and be fine.

If you want to put the additive just as insurance, go ahead. It can be a good idea. Next time change the fluid.