1 month old truck, had a clunk, but only noticed it once in a while in the rear. Was installing an in-bed wiring harness today, and saw my spare tire was hanging down about an inch! lol I'm guessing when they installed the 5th wheel hitch, they had to lower or remove it, and never got put back up all the way. Or else just came that way from the factory, but guessing it was from the hitch install. Not sure why it didn't make MORE noise, only heard it a few times. Figured I would have it checked at the oil change next week, but I found it myself..