I own a 89' RS Camaro with a 2.8 L V6. It has a 5 speed. According to your tech data it has a 3.42 rear axle. What gear ratios came with posi? I thought they were the 3.73 and 3.42. How do i know if it has posi or not, other than the fact that both wheels spin at once? Any help would be greatly appreciated, thanks

 

There's no direct association of posi with gear ratio. There's 2.73 posi, and 3.73 non-posi, that come in these cars.

Forget the BS about jack the car up and turn this and see what that does, or whether it lays 2 patches of rubber, or above all, the codes; take off the cover and look. Have you changed the fluid lately? Then the cover needs to come off anyway. Look at the carrier while you're maintaining your car. Use synthetic fluid; it's often good for an extra mile or 2 per gallon.

 

or you could look at your rpo sheet. G80 is the code for posi rear....providing you have the stock rearend in your car.

 

i dropped a rear end into my 89 tbi from an 89 v-6. The axle code was 6HL. I couldnt believe the difference and overall feel of the new (used) rear end in my car. When I would do burn outs both tires would rip loose and leave two patches of rubber on the ground. But with the car jacked up one side would spin one way and the other side the other way. I decided that I needed to open the cover up and change the fluid anyways. I also wanted to inspect for damage and signs of excessive wear. Everything in there looked good excepted for the open differential staring me in the face when i opened the cover up. Just open her up and see. It's part of routine maintance anyways.