1989 Trans Am GTA w/ factory POSI

My posi is completely worn out and killing my traction around corners and ability to put power down without spinning one tire. Does anyone have an opinion on what replacement is best for this? I haven't worked much with the rear end of my car so I'm fairly uneducated on what exactly is worn out and what to replace (the carrier maybe?). I've seen Auburn and Eaton so far as options. Thank you for your help and advice!

 

If you have the 9 bolt you have very limited options. If u have the 10 bolt, the detroit trutrac is the way to go.

 

First thing you need to know is which rear end you have. Your car could have the GM 7.5 10 bolt or it could have the Borg Warner 9 bolt. These are two completely different rear ends and no parts will interchange.

If you have the 9 bolt you can have your Borg Warner unit reconditioned so that it will work again. This requires some machine work and shimming to get the cones to lock again.

If you have the GM 10 bolt then there are several options. The Eaton Posi is good for street/strip use. The Eaton Truetrac and the Torsen are good for street and auto cross. The Auburn is good if you like throwing money in the trash and rebuilding the rear end often.

 

Detroit tru-trac or if youre lucky and stumble upon a Zexel torsen unit. I've had my torsen posi since 2005 and it has seen nitrous, a procharger and now twin turbos and it has never skipped a beat.

 

I went with the Eaton Posi. for my street car = http://www.eaton.com/Eaton/ProductsS...posi/index.htm
Link to the build = https://www.thirdgen.org/forums/tran...de-photos.html
Its controlled using torque meaning I don't have to wait for a slip. Both tires are pushing the car just by stepping on the gas .