Well I just picked up an '89 GTA to replace my totaled TA. I got it home and drove it for a while and the only thing I could find wrong with it mechanically is a bad trans mount, in which case I never got on the gas hard for fear of slapping the yoke on the floorpan. Well I replaced the trans mount and stretched the car's feet a little and found out that the Borg Warner 9-bolt 3.27 posi is toast. It takes roughly 30 ft-lbs to turn the wheel when the other is locked, and according to 9-bolt.com, 35 is minimum. This rear end has 83,000 miles on it.

Well conveniently enough, out of my old TA came a perfectly working 3.27 Borg Warner 9-bolt posi but it has the old style rear disc brakes, 133,000 miles on it, and 100 ft-lbs wont budge the posi, so thats good.

My question is should I...

A: Just swap the rear ends completely and trade over brake parts from the 89's PBR's.
B: Steal just the posi cones to put in the GTA's rear since the rest of the spare 9-bolt I have has another almost 60,000 miles on it?
C: Rebuild the posi thats currently in the GTA with the $155 kit from 9-bolt.com?
D: an other suggestions you guys have.

Now I know some of you may say that I do not need a posi for street driving, but I am very **** about my cars and just the fact that something isnt working correctly bothers the hell out of me.

So basically I want the strongest and best 9-bolt I can get by combining parts from the two rears I have. I dont want to spend more than the $155 from 9-bolt.com for the new friction pieces/springs or what I can do with a welder to strengthen it up. Thanks for your help in advance guys, this board is probably one of the best resources a car guy could ask for.

-Adam

 

Option A -- The PBR rear brakes/rotors are the most effective stock calipers, so just swap them onto the replacement rear along with the backing plates and dump the morane iron calipers. Replace the cones in the weak diff and put them in storage as replacements.

 

Alright good thats the option I was leaning towards. Thanks for the help. Plus that option works out well because that rear is already out of the car so I can make it look pretty, clean it out good and fix everything up while keeping the car driveable.

One question though, On the rear end I pulled from my old TA, I noticed reminents of red paint on it that almost appeared to be factory. Were any of the Borg Warner rear ends ever painted red from the factory?