So, I just bought this truck. 2007 with 60K on it. I noticed "sometimes" when I stop quickly and/or just slow down normally and jab the brakes when almost stopped I hear a clunk in the rear end. it's almost a sounf and feeling like I'm towing something when I stop and the hitch slides towards the truck. Those that tow will definitely know what I'm talking about. Is this normal for these trucks? Thanks for any and all comments.