ok, i have a 91 camaro z28 that came with a 350. as far as i know it still has the factory posi rear end and gears. i went to do a burnout today and only the passenger side wheel spun. i was curious so i did another one and with the same results. my question is what can cause only one side of a posi rear end to break loose?? i know it has posi because last fall i burnt a set of old tires off the back and left 2 lines of rubber on the road. any help or direction would be greatly appreciated.

 

Worn out. BTW, under the right circumstances even an open will spin both tires. To be sure that you have a limited slip, check the link below:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

ok, i'll jack the rear end up and double check to be sure it is limited slip. And secondly, is there a way to fix a worn out posi unit?? or am i better off to just replace the whole rear?? thanks in advance

 

If you have the stock factory GM posi be careful. Mine did the same thing whereby you questioned whether you had posi or not and then I started to hear a slight worn bearing, grinding sound. That cone type posi wore their metal and fatigued the axle retaining pin and then it broke. Locked up and caused severe damage. Pull your rear plate off and check for metal fines.

 

ok, i'll pull the cover and check. i just jacked the back of the car up and when i turn one wheel the other follows in the same direction indicating a posi. while it was up i checked and it has 3.23 gears. so my next question is whether this rear end is salvageable i.e. can it be repaired? or is it time to start looking for a new rear? any input is greatly appreciated!! thanks

Tyler F.

 

The Auburn, which I assume you have (check the pics in the link I provide above), can't be repaired, but it can be replaced. big gear head, who knows his stuff, recommends Easton.

JamesC

 

I have a 91 and my original was 3.23. I replaced it with an Auburn posi. Has worked well so far, posi always engages. When I put in the T56 I changed to 3.73.

 

You should have the Auburn differnetial, which can not be rebuilt. I don't recommend replacing it with another Auburn because they don't hold up well, can't be rebuilt and they fill your rear end with metal as they wear. You will see that when you go to replace it. You have 3.23 gears, which are 3 series, so you can use a new Eaton Posi. This is a MUCH better differential than the Auburn. All you need to do is replace the Auburn and clean out the metal from the axle tubes and the bottom of the housing. Replace any bearings that are worn. Here is how to replace the differential.
http://www.nastyz28.com/forum/showth...t=install+posi

 

id figure id add onto a thread instead of makeing one
on my car i get one tire fire, i jacked up the pumpkin and spun a tire and the other tire just stayed in place the tire i spun would make about 3/4 a turn freely and the other 1/4 turn felt real stiff but i could spin on
also the diff seemed to be makeing a weak whining noise i know it leaks a bit from the fluid i see running down the axle which will get fixed but could i have a open diff or a worn/broke limited slip

posts would be appreciated thanks

 

Could be anything. The only way to know is to remove the cover and look at it.