I have a '91 GTA. I've only put 1.5 K on it, so I never noticed that when I was doing burnouts, I was only smoking one tire. My friends pointed this out to me the other day.

When I take off (not spinning tires), the car starts going, and then pulls to the other side a little bit. My uncle was riding in the car and said it felt like a posi. But, if I had a posi, i dont think my car would only be smoking one wheel.

I feel like an idiot, cuz i've just been wasting rubber, and its only been on one tire I really gotta stop burning out, even when I get this problem fixed.

Anyway.... Is it possible I just have a worn limited slip? (My car only as 50 K on it) Or is my GTA a "one wheel wonder" from the factory?

In either case, how can I get both rear wheels to drive the car? I am considering a locker, but I want to modify my car for street/track/auto x. Are lockers a drag race only thing, or are they good for the track too? What are my other options? Can anyone reccomend a specific product/brand?

Thanks!
Bill

 

of coarse posi's can go out.

heres an easy way to tell, its always worked for me.

jack up the rear end, if you turn one wheel, the other wheel will turn the opposite way regardless, now if you jerk the one wheel one direction, the other wheel should catch and both rotate at the same time. you can try that. they will only spin the same way if it is a posi though.

 

So... I could possibly have a posi rear from the factory? That was an option?

You're saying if I turn one rear wheel slowly, the other one will turn the other way. But, if I start one real turning very suddenly, then they should both turn the same direction if it's a posi. Is this correct?

This is a stupid question, but I have only had the car for a short while. What part of the car should I use as a jack point?

If my car fails this posi test, is it possible I have a limited slip?

Any suggestions on what I can put on my car to fix my "one wheel wonder" if it fails the posi test?

Thanks again!
Bill

 

yes that is correct you understand the way to test if you have a working posi or not.

yes many cars came factory with posi, chances your gta has it is good.

you can jack up the car from the differential for a quick test like that.

if it fails the test, take it to a shop and pay alot to rebuild it, or get a new axle?


you can get your rpo codes usually found in the glove box, and check the codes online for the one that calls it a posi axle option.

 

To be certain, pop the diff cover and take a look. It may be time for new lube anyway.

JamesC

 

I had the fluid in the rear diff changed about 1500 K ago, and I had it done at a dealer so I dont want to waste that money by draining out the fluid.

If I were to open it up, what would I be looking for to let me know it does/does not have a limited slip or posi rear.

Finally,
Can anyone reccomend a part/upgrade/other to get me a positraction/limited slip that's good for street/track use?

Thanks!
Bill

 

Here's what you'd see:

https://www.thirdgen.org/techbb2/sho...d+slip+and+pic

JamesC

 

If I don't have that, can I install that in my rear diff? Or do I need a whole new rear diff?

 

The "best" idea is to look (who knows what may have been done to the car along the way), but check your RPO's. A G80 is limited slip. A limited slip rear end should have a metal tag on the diff cover (might say something about a limited slip additive). The tag can be seen in the following link, if you look closely, under the left e-brake guide:

https://www.thirdgen.org/techbb2/sho...hreadid=249098

JamesC

 

As for reccomendations most would reccomend an eaton posi rearend or the auburn *pro* posi. Both are great differentials for street posi setup it seems.

As for lockers it's more overkill for what you are doing and most of them are noisy while cornering and locking up.

ps.

wouldn't a worn out posi unit act the same with the tire spinning test? Or would even a worn posi catch enough that with no load on the wheels it would turn both?

ps2 so you know some rearends i've spun don't spin in opposites but, spin just 1 wheel so you don't freak out if yours does this though. Although it can be caused by bad wheels bearings and other wornout rearend parts which you need to know about but, figured i'd tell you so you don't think it's the end of the world.