Well, I have a 97 Z w/ 3.42s, ABS and Traction Control. I just wanted to state that so you know what I'm workin’ with.

Anyway, for the last 2 months, my rear end, has been whining and making a lot of noise. I don’t know what it could be. 2 months before it started making noise, I had a local Chevy dealer change the fluid in it and when I got it back it would make a slight noise when I would turn. But now its making all sorts of noise and is mostly noticed at highway speeds. I just wonder if I let it go for too long and if it’s repairable.

I want to try and replace the fluid again and clean up the area up and see if that helps. What are my options if that doesn’t help keeping in mind that I don't drag, race or drive my car hard, so a stock replacement would work for me. Any ideas or thought?

Thanks,
Daniel

 

Sounds like they either didn't put enough fluid in, or didn't add GM limited slip additive. Try changing the fluid and YOU MUST add GM limited slip additive. Good luck.

 

Thanks for the reply Cmr0z28.


I did a search on the board and found these part numbers:

Limited slip additive
-GM PN : 1052358

Housing cover Gasket
-Felpro : RDS 55072
-GM PN : 26016661

Any others that I need? I couldn't find the PN for the gear oil though.



Now that I'm thinking about it, I wonder if the tech at the dealership where I had the car worked on added the additive. Is there a way I can find out? I'm guessing its too late now since its all been mixed in with the rest of the fluids. Any ideas?

 

This is ONLY a thought, Dan, you say your car has > 100,000 miles and you're the second owner?

I wouldn't chase the problem too far before I checked on a new aftermarket rear.

Additive is available just about everywhere, GM, any parts store.

Good Luck

Steve

 

If you're gonna swap fluid why not upgrade it to something like Morroso "climbing gear lube" available at Jegs like $8/bottle and limited slip additive as well.

 

For the gear oil, there is no "special" part number.

Many people use Royal Purple, Redline Synthetic, Mobil 1, and other high dollar (comparitively) brands.

Me? I use standard Castrol Hypoy-C 75w-90 gear oil in mine and don't have any problems.

Might I recommend when you get ready to fill it, put a little of the gear oil in the case (a few ounces - less than 1/4 bottle), then add the GM additive to the gear oil, and push the rest of that bottle into the case. Then move to the next bottle. I find that it works easier for me and I end up with less mess that way.

Good luck!

 

Im using Penzoil w/ additive and no probs with 4.10 gears

 

valvoline with additive, no weird sounds, 4.10