Hey guys, I've been noticing some drips on the ground under my rear diff. I knew my Diff cover had been leaking, but I decided to get under the car to look anyway. Turns out it's also leaking from the front of the diff (near where the drive shaft yoke is).

Where can I find the seal that goes here? And how hard of a job is it to change it?

https://drive.google.com/open?id=0B1...V9nY0RTQmpVT28

https://drive.google.com/open?id=0B1...FpJQno1US1HSG8

 

I believe that you will have to remove the whole diff to replace the front yoke seal.
but I would consider replacing all the seals, bearings and check the side yokes for wear while you have it from under the car.

I just rebuilt mine with the papers from Gary (gtr1999) that you will find here on the forum, it's not easy but if you follow the papers you can easely do it yourself .

 

The seal is available from your local auto parts store. The seal can be replaced with the differential in the car. I have done it. It is a very difficult job due to clearance issues and, without relevant skills or an abundance of knowledge, the high probability that you will not have a good outcome. I would suggest that you remove the differential from the car (since the rear gasket too is leaking) and have a shop that does differential repair do the work. Removing the differential is unto itself a difficult job, but it's more a matter of labor rather than specialized skill.

If you want to know why I recommend you farm out the work, do an Internet search on replacing a differential pinion seal to better understand the pitfalls in doing the work for a successful outcome. A C3 pinion seal is no different than any other manufacturer's seal so whatever you discover online will be relevant. If done wrong, you might still have a leak or a newly acquired whine from the differential. Once you have that information, get under the car and have a look at what I mean when I write of the obstacles.

 

Thanks for the info guys. I think I'll go ahead and tackle it myself, doesn't look nearly as bad as some of the other jobs I've done on this car.


What model differential do I have (1979 with 3.55 rear gears)? Just want to check so I get the correct seals.

 

willcox or for a complete set http://www.bairscorvette.com/c3reare...tialparts.html

 

Lots of info in the archives

 

I agree, but prepare yourself. I have both a whine and leak at the pinion. Side yokes are good. The differential has been out three times and returned to the vendor over about a two year period. In my case the time I had to work on the car was limited by work and cold weather. So now I am living with what I am telling myself if a pinion weep but the car still marks it's spot. Am I unhappy? Yes, but I'm also tired of pulling the dam thing out. Please do more research than I did because it is not cheap.

 

Here's a tip when removing, and later installing the rear, the threads in the carrier are 3/8-16, and what I found was helpful was to remove two of the bolts one on each side and replace them with studs, (bolts with their heads cut off). These studs are on the carrier side. I slotted the ends so they can be screwed in with a straight blade screwdriver.