While doing a post flight inspection of the chassis oiling system I noticed that 1 of the 8 bolts that hold the short shaft between the transmission and transfer case was missing and 6 of the other 7 were loose. Not good. These have the milspec lock nuts on them. Do these lock nuts loose tension over time and need to be replaced with new? I'm going back under the truck and put a wrench on everything I can find to make sure all is tight. I got this truck in February from the Florida NG thru GL.