Can anyone steer me to a site where I can see the Service Manual for the PF 4WD, 2001. I want to look specifically at the transfer case and the drain and fill plug. I have a shuddering/vibration at 45+mph. Just developed this last week. Mechanic and Dealer tell me that it probably needs a new Transfer Case !!!. Metro 727 - a member here, informs that it may the "U" joint. There is no noise coming from the TC & it can shift into 4WD. The vibration is worse in AUTO mode vs. 2WD mode, but vibration is still evident. I Think metro 727 is right!!. A relative of mine told me that certainly maybe the problem. But the plug is pretty much "frozen' on the TC.