Have you changed the rear end fluid ? If it's a limited slip, I would change the fluid ASAP and don't forget the 4oz. bottle of friction modifier from Mopar.I've noticed that everytime I backup or drive my 03 q-cab around a slow curve I get a groaning sound coming from my rear end. Anyone have any ideas? I was wondering if it might be the lsd and a common noise for these trucks or not.