Posi Rear or not

[olds87]

Is there a way to see if a car have a posi rear or not? One time I had the car on jack standsto check to see if the rear wheels are warp or not. Put it in reversee and left rear tire spin and the right rear stand still. Put it in drive and both wheels spin. I think do have a posi in the rear from factory.

[barno68]

You should be able to tell from the differential code stamped on the axle tube or housing. Once you have that, just do a web search for the codes for your year of car.

Brent

[eville]

Jack the car up to get the rear wheels off the ground. Put the tranny in neutral, engine off.
Turn one rear wheel by hand. If the other wheel turns the same direction, posi. If the other wheel turns the opposite direction, open.

[slowcamaro]

Change the diff fluid is the easiest way to find out for sure :-P

[BA.]

I do what eville does.

[olds87]

Thanks for asking my qusetion guys.

[MuscleRodz]

The only sure fire way is to open up the rear and verify if there is a clutch and spring pack in the dif.

Mike

[big gear head]

Mike is right, this is the only way to be sure. A posi with worn out clutches will act just like a standard differential and a damaged standard differential can act like a posi with the wheels off of the ground.