hmmwv m998 help and advice

[johnm998]

hey I'm new here but I recently acquired a 1989 m998 turtle shell hmmwv from a surplus contractor it had thirty six thousand miles upon purchase when I first got it last summer I noticed what seemed to be a excessive grinding noise in the back right gear hub but once the weather got colder it seemed to vanish but now with the oncoming heat of summer the grinding is back I took it to the local machanic and he just kinda shrugged his arms and was afraid to mess with it so I dropped another 1k on it and purchased a new gear hub assembly this did not fix the problem it only seems to do it at exactly the same points in the road and that gear hub in particularly is always hotter than the rest I've tried just about everything from replacing ball joints to changing fluids and greasing fittings do to my exstreme rural location and terrible road conditions this truck replaced my nissian as my everyday driver I've have scowared the forums and cant seem to find anybody with a similar issue any help or advice would be appreciated