[440dakota]

what you have is a rear end with a limited slip differential. it is not an open diff and it is not a complete detroit locker setup. basically, when your on the gas it locks the rear two wheels so that they spin together. when your not on the gas a lot, they spin as an open diff. allowing you to take a turn or whatever. the problem is when it's locked, they want to spin the exactly the same. however, uneven tire pressure or turning slightly or whatever forces the wheel to skip on the pavement breaking traction and causeing the wheel to hop. hope this cleared it up.