I can almost guarantee it's your halfshaft. I had that same problem with my Honda 2 times, and since the guys say that ur truck has halfshafts, then I am vouching for that. It can only get worse, and if you keep driving it you may find yourself on the side of the road with your tire at an \ angle. They're like I'm guessin $65 at an auto parts store, and another $80-ish to get installed...
Good luck!
Good thing this is a 4x4 we're talking about, if the halfshaft goes, he'll just be driving i 2wd for a while
4x4 IFS has no support on the halfshaft, so if the axle breaks, the wheel is still completely held on by the A-arms
