I can feel a weird rumble or shudder under my feet while going over bumps, problem is when I'm stopped or just BARELY rolling I can hear the actual rumble, it kinda happens when I turn the wheel but then not all the time. I was under there today, everything is tight, my het shield was rubbing on my fornt drive shaft and was wearing grooves in the shaft, but I bent it back, but the sound/feel is still there. Also when I slam my door I can hear something rumble.....

 

have someone open and close your door while your under the truck to listen for the problem.