Posi-traction upgrade worn out due to being able to turn SC wheels by hand on lift?

[octanemaestro]

The previous owner told me that he loved the posi-traction upgrade in the transmission. The mechanic told me he feels that the posi-traction is worn out because he is capable of turning the rear wheels in unison by turning one side when on the lift. (Note: Unlike without posi-traction turning one wheel would cause the opposing wheel to turn the opposite direction, but he is saying you shouldn't be able to turn either one by hand.)

Is his assessment correct?

[zedsn]

In a regular limited slip rear end the way to tell if the rear has a limited slip is to turn one wheel by hand and if the other goes in the same direction the car has limited slip. I would think that this would still apply to these porsche boxes as well.

[jamesjedi]

Posi traction = limited slip differential?


In unison = limited slip differential

[porsche930dude]

if it is worn out it will turn opposite while in gear like an open diff.

[zedsn]

He is saying that his mechanic is saying that if he can turn the rear wheels it is not a posi or limited slip which I believe to be false.

[mreid]

Posi-traction is a GM trademark. You mean limited slip. Your "mechanic" demonstrated that you have limited slip differential. He also demonstrated that you need a new mechanic.

[zedsn]

Exactly!

[trond]

your limited slip is OK, your mechanic need replacement

[Plays with cars]

Very familiar with clutch type differentials from my years with muscle cars, but what is the behavior for a diff with a Quaife (torque biasing) type differential? What should you expect to happen to the opposite wheel when turning a wheel on a lift?

[eshtog]

Originally Posted by mreid

posi-traction is a gm trademark. You mean limited slip. Your "mechanic" demonstrated that you have limited slip differential. He also demonstrated that you need a new mechanic.

Originally Posted by trond

your limited slip is ok, your mechanic need replacement

lol

[Ouzo12]

The title reminds me of the time a guy told a Venezuelan friend of mine that he once had a Camaro with posi traction, mags and a hurst. My friend looked perplexed until I explained: he had a Camaro with a limited slip differential, rims and a short shifter, ha!