Just bought an 04 1500 4x4 with 115kmi yesterday (to replace my beloved '99 'burb). Drove nice and quiet during the test drive though I did note a slight "click" when initially engaging power to the train. Thought maybe there was slight play in one or more U joint so I wasn't too worried about that. Today (all packed up for a weekend at the coast with the new truck) we started driving out of town up a long hill and there was a fairly loud clicking/clanging sound above 30mph. So I had my gf switch back and forth from "D" to "R" while I was under and located the click/clang sound from where the drive shaft goes into the rear differential and could see the drive shaft rock back and forth and seemed to have quite a bit of play. No leaks detected. Any help or advice would be GREATLY appreciated!