Rear Pinion Seal Leak

[vetter1986]

My 86 Vette rear pinion seal keeps leaking on the exhaust giving that burnt 80/90 smell. I have replaced the seal once already and it is leaking again. Whe n I replaced it the first time, I noticed the driveshaft ujoints were stiff. I replaced these also. This only lasted about 6 months and it is leaking again. There are no burrs on the yoke seal area and the pinoin bearings are smooth and are not loose. Has anyone else ran into this problem and if you have, what was done to correct it. Thanks in advance.

[robert kirk]

I had this problem with a 69 years ago. It turned out the driveshaft was out of round, not bent, egg shaped. I would lose a pinion seal every 3 months. Took the rearend apart changed bearings, reset clearance's, same thing. finally took the driveshaft down to check the balance and the shop found it. What the dynamics behind this were to cause this i don't know. I have never had it happen before or sence. It was a BB car, and yes it was raced. There was never any vibration, no signs at all that this was the problem. It never wore u-joints, nothing just the seal leaking. My guess is somewhere in the past bubba locked the driveshaft in a vice to work on it. They cut the ends off and made a new center section, balanced it, no more problem. I kept the car about 3 more years, raced it hard no problem, never had another leak. I know this is not the average answer but problems like this can turn out to be some really weird things. When working on a old car you never know what the mechanical ability of the person in front of you was, so i have learned to take nothing for granted. robert

[vms4evr]

Ah yes, Eau d'90 Weight. What an awesome manly cologne. With the leak on the pipes and a couple of dabs behind the ears and you'll be just catching the women like flies

I had the gears swapped out a little over a year ago. Everything was fine until a couple of months ago. Then the leak. Just enough so that when you get out of the car you notice it. Nasty... Crawled under the car and saw the stains on the exhaust pipes.

Took it down to my mech and he got one of the transmission shop guys to go over it because he couldn't find the leak. When the guy dropped the drive shaft and checked he said the pinion nut hadn't been torqued down and lock-tite applied and it was starting to loosen. He also noticed that a new seal didn't fit as well as he thought it should. He put sealer around the metal body of the seal and set it in place. Then let it dry overnight. Put it all back together the next day and it's been fine so far. Probably about 2-3 months now. I have done a couple of autox events and it is a daily driver. No leaks so far.

Graham

[vettl83]

Had the same problem with the 84 CF, turned out to be a worn out pinion yoke. The car would howel under deaccelleration "off load," and would sound ok under accelleration "load." As long as I was in the neighborhood I replaced all the bearings and seals too. 84 CF 91 ZR-1

[jeepie]

Are you sure it is the seal, a couple of the case bolts on my dif were loose and caused the seam to leak and drip on the pipes, I thought it was the seal too.
Might be worth a check.