Healthy Differential Test?

How can I find out if my LSD is in good mechanical condition or not?

Burnout!

Seriously, it's a pretty good test. If your tires leave two solid stripes, it's working. :)

Burnout!

Seriously, it's a pretty good test. If your tires leave two solid stripes, it's working. :)




Not always true. A blown posi unit can still leave two solid STRAIGHT stripes, but put pressure on one side or the other and one wheel will stop "spinning."


Jack the rear of your car up and put it in neutral. Spin one tire by hand and if the other tire spins IN THE SAME DIRECTION, you have a working LSD. If the other tire spins IN THE OPPOSITE DIRECTION you have an LSD that is not working correctly, but might still lay two solid straight tire marks.

Okay, and to find out what size rear gears I have I jack the car up and turn the drive shaft and count the rotations until the rear wheel does a complete circle right?

Correct... easiest way it to make a couple marks under the car with chalk or something. Make one mark on the backside of the tire and a corresponding mark somewhere that you can see while you are turning the DS so that when the lines lineup you know you have gone one complete rotation. Also a mark somewhere on the drive shaft with a corresponding mark somewhere so that you know every time you make a rotation and how far past the original spot the DS stops after one complete rotation of the tires.

My question is if I burnout only sometimes I leave 2 black stripes...and when I try cookies only 1 tires smokes??? this is bad right?

My question is if I burnout only sometimes I leave 2 black stripes...and when I try cookies only 1 tires smokes??? this is bad right?

Yep. See post #3. :)