I just got back from the dealership where they changed the fluid in the diffs and Xfer case. My wife drove the truck (01 Durango) home and of course she doesnt notice anything as long as it moves from point a to point b. I, on the other hand just took it to the grocery store and there is an awful grinding and "rubbing" sound coming from the rear diff. It only happens when turning. Im thinking the idiots at the dealership forgot to add the limited slip additive. As it sure as hell wasnt doing it before hand. Do you guys think that this is the case? If so, do I have to use MOPAR additive, or can I run to Auto Zone and get a tube and squeeze it in there. I just dont have much time to take the truck back to the dealership for another day. Thanks for the help.