Im looking to get a posi disc brake rearend but the rearend is already out of the donor car. How do you guarantee its a posi without putting it back in and smokin the tires?

 

Remove the cover and look inside. This is the ONLY way to be sure. Believe me, I have used the other quick methods before and lost money because they are not reliable. Spinning the axles might work sometimes, but other times it will cost you.

 

Take the cover off before paying for a LIMITED SLIP rear. It should look like this.

 

Do you have a picture of what I should be looking for in a posi?

 

More info in the following FAQ:

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

JamesC

 

http://rides.webshots.com/album/55410292AnMJrE
Take a look at these. The Auburn and Governor Lock were the only limited slip (posi) differentials used in the third gen Camaros and Firebirds. Someone could have installed something else over the years, so be sure to check it out.

 

Not the only! How about the 9bolt borg warner!

 

Stay away from the gov lock and avoid the 2 series posi's.

 

What do you think that above picture is???????

 

OK, the Auburn and Gov Lock were the only ones available in the 10 bolt. The 9 bolt had the Borg Warner limited slip, which is a cone type, like the Auburn. The point that I was trying to make was that the Eaton Posi was not used in the thrid gen. The Eaton Posi is available now in 26 and 28 spline versions. It's my opinion that the Eaton Posi is the best street/strip limited slip differential for high performance GM cars.

 

Thanks for the help so far. But what is the difference between the Auburn and the Gov lock? And which is preferred?

 

Neither one is prefered. The Gov Lock is fragile and the Auburn will wear out, is not rebuildable, and will fill the rear end with powdered metal. The Eaton Posi is prefered. The Gov Lock is kind of rare. They usually break the gear oon the governor and then they just spin one wheel. Most had the Auburn. The problem is that you can't tell how close the Auburn is from being worn out. It might work fine for a few months and then stop working. When it wears out it will still drive the car, but will only spin one wheel.

The best thing to do is install a new Eaton in a rear end that has the gear ratio that you want. If you are just wanting a bolt in rear end that you don't have to do anything to then just pick one with the Auburn or Gov Lock and hope for the best. They held up pretty well for many people while these cars were new.

 

Thanks for the info.

 

So what would be better a rearend from a third gen or a 4th gen

 

I answered that in your thread.