It sounds like it's coming from the tailgate which I don't believe it is. Started after a 4 wheeling trip. Went through some manditory mud crossings and dropped on each side of the rear bumper. Got home, cleaned off all the dirt and rock (i think) from the undercarriage, inside of bumpers etc. Now I've got this rattle that comes from the rear of the truck when I'm going about 10 mph and turning right. I also get it when I shut off the engine. The truck does a quick rattle to stop. The driveshaft is tight, the rear gate is tight, and I don't know what to look for. Any ideas?