Don't everyone yell at me at once when I ask this...

I had the rear end apart apart when we restored the car 2500 miles ago. And my "mechanic" (I'm since using new words to describe him) left me with lots of little problems, leaks and issues, mostly due to cheap parts and/or the wrong care factor. Anyway, my current leak is coming from the differential. Pretty hard to tell exactly where yet as I have not removed anything and stuff is pretty well hidden.. but there is the stubby shaft (does it have a name?) that sticks down and it has an oily feel to it, so the drip is eventually coming down to it and onto the floor. It's almost more of a seep than a leak, as it leave a stain, but not every time (getting worse). Searched the forum and found good stuff on how to disassemble it all but before i do that, are there any additives that might stop the seep? (that was the part where i don't want everyone to yell at me)

It's summertime, I have a zillion other things to do, don't want to tie up my weekend (if it went really well) on this, and we honestly do not have any reputable C3 mechanics close to me.... Would love to limp along (even if I have to add fluid from time to time) till winter. (and I have no idea if the mechanic put the right stuff in it to begin with.

All opininions and advice welcome!

 

Probably a pinion seal leak. Sounds like your guy wasn't too familar with differentials. Could be simply no sealant on the pinion splines, could also be cheap seal, lousy install practices, worn yoke OD, or something created by the mechanic.
Leaks could also be from the side yoke seal or cover but usually it's the pinion seal. Nothing is going to stop the leak. You either live with it or replace it. Since you question his ability then I would be more concerned on how the job was done and what parts were used. Did you get a parts list with it?

 

Man I hate doing that work and then finding somthing is WRONG. I had A small leak not really sure where, looked like the Cover ,take it off no easy job check gears and everything looks good.
Seal it all back up still leaking,Take it back apart this time at my house not at work well when I sprayed Compressed air in the bolt holes I got sprayed in the face with lube go figure looking closer I relized the tapped the cover plate hole all the way throuh and the oil was just coming right out of the bolts in the back used some permatex "the right stuff "filled the holes put it all back together 2 yrs ago still no leaks .You think they could have come up with an easier to work on better and longer lasting Rear end on A car like the Corvette. any way good luck on finding the leak.

 

Lon
That's from using spring bolts that were too long, cracks the inside of the boss in the cover.

 

Agree with above. It's most likely the pinion seal. Is she slinging gear oil in the tunnel?

But check for simple first. You might try some teflon tape around the threads of the fill plug. Secondly, make sure Bubba (I'm sorry, "mechanic with a little m") installed the little vent on top of the carrier housing.

Good luck!

 

I just went thru some of this on my 78 and the fill plug calls for a gasket (cork). Wilcox sells em for $4.00. I noticed before I used it and had the differential full, that it leaked until I installed the gasket.

I'm not saying that's the problem...but its a source of leakage.

 

Geez...I hope we haven't gotten that bad that people don't won't to ask a question cause they are afraid they'll get yelled at. I don't think there is an easy solution to this and as described I suspect is a pinion shaft seal leak. There's a stubby axle that goes into the differential. Wilcox has some instructions to show how to gain access to this but you're dropping, the exhause, spare tire tub, spring, crossmember and differential to gain access to the shaft seal.

I don't think the fill plug would run down the half-shaft and drip as you describe. And I know of no additives to decrease the leak. If you're not driving it...it should stop leaking. I don't think they got the fluid so full that its spilling down the axle to the half-shaft.

 

One other thing it could be. Overfilled. When I first bought my '77, I changed the diff. fluid, and refilled it, all with the car jacked up on the right side. Days later I noticed gear oil seeping from around the side yokes. I removed the fill plug with the car sitting on level concrete, not jacked up, and quite a bit of oil drained out. Once it drained down to where it was level with the bottom of the plug hole, I plugged it back up and it hasn't leaked since. Something to check before you tear it apart.
KC

 

thanks all for all of the knowledge. I'm "enough" of a mechanic to check for overfilled...leaking (no gasket or tefflon tape around the fill plug) and the vent (although I don't know what I'm looking for) on top of the housing.. But if it needs dropped and new gaskets and such, I'll be looking for competent help (unless you guys tell me that any dummy can do it if he follows instructions?)... I have a hoist, so getting under for inspection is easy... Last night we ran over a fresh killed deer carcass... STINK...as we were driving home, so had to pick out deer guts and fir today... Differential took a back seat to cleaning!

Thanks again for all the help! and where do I look for "pinion seal" leak?