I'm getting ready to order a set of Yukon 3.42's from Randy's Ring and Pinion. A question they asked me was if I have a posi or standard rear end. Is there anyway I can figure this out by just looking at it? I know if I do a burn out and there are two tire marks the same length that I have a posi, but unfortunately I can't do that right now. So is there any other way to tell? Please let me know. I'm running a 95 A4 if that helps. It's in my sig. thanks!

 

All V8 4th Gen F-Body's left the factory with a limited slip (posi) differential. Do you have any reason to believe that yours is not the one the car came with?

There should be an RPO code for the limited slip on the build tag.... not sure what ith "code" is, but it might be worth looking it up in one of the online sources.

EDIT: I think its "G80"

 

Chock the front wheels and jack the car up using a trolley jack under the back axle( tyres just off the tarmac).
With the auto in neutral turn one rear wheel the other should go in the same direction. Its a posi.
If it goes in the opposite direction it's a standard diff. Far as I know this works for all posi's & locker diffs.

But as has been said all Z28 are posi's

Andy

http://www.cardomain.com/memberpage/441297

http://www.cardomain.com/memberpage/537476

 

So would you say my car has a limited slip posi or just a posi? I'm slightly confused on it. I will jack my car up and check it with that test as well thanks. I think my car does have the factory rear end (a posi), but i'm just curious now if it has a limited slip diff. or not.

 

Limited slip, posi, same difference as far as GM uses the terms.

 

Can the posi stop working? Or fi that happened would the entire rear end be "dead"?

I was looking at my tires, about to get new ones, and my right rear tire is BALD as hell in the middle..theres tread on the side though.. then i went over to the left side and it was low, but nowhere near the slick the right was..