So yesterday I had to go pull my friends jeep out of the spot it was stuck (its a jeep thing, I wouldn't understand ) and the rear end made some wierd noise. I hooked on, went to pull up the slack, and only one rear tire was turning. I rocked it back and fourth a bit when all of a sudden there was a terrible whine from the rear end and the posi kicked in. Could I have messed it up? Is this normal? I recently changed the fluid and added the limited slip snot. Any thoughts?