Do this to see if you have LSD:

Jack up the rear end of your car. Spin one wheel, *the wheel should spin freely, and the other side should not turn at all*. Now go to the other side and spin the other wheel, *both wheels should turn*.

To see if you need to replace your LSD. While doing the test, there should be ZERO play on the wheel. IF the wheel has a little play or a lot of play on it, you might want to check up on the LSD.

Peace,
AJ ^_^

 

Yep Aj is right. His method is the safest.

The other big thing to remember is that on a conventional diff if you rotate one wheel with the car not running, the other wheel will move in the opposite direction.