alright i got an auburn pro posi awile back... anyway, i decided to do the first burnout since i got it. i stop the truck, put the break to the floor, and punch the gas. all it did was bounce a bunch of times in a row, felt like i was in a damn jetwash in a plane . the tires never came loose, should this happen?

 

Yea don't hold the brake to the floor, just enough to stop it. It will do it. Mine did it stock out of the showroom. Till the rear hits 20 MPH anyway, then one wheel peel, hehe (G80 locker)

 

Basically you just stall tested it..... At some point did the RPM taper like 2000 2200 or so? Put it in "L1" and try again. Remember the point of the posi is to have traction, not like the overestimated potential of my G80 that continues to impress me when it unlocks and makes my truck look like it has a single spinner

 

The bouncing you described is called 'wheel hop' and it is VERY bad for the drive line. So dont do it anymore untill you get it fixed. I have some U clamps pulling the factory helperspring up to the two leaf springs. You can get the U clamps at auto zone for $10.oo and its well worth it for improving the rear suspension untill you can swing the cash for some real suspension.