You'll need to look at a few things, and don't bet its at the rear.
Chock your tire and put the jeep in nuetral, then check the shafts, both front and rear shafts, there should be 0.0 movement in the joints, take hold of the shaft and then the end yoke at the diff and twist them opposingly, do the same at the t-case end with the slip and shaft.
Then do the same at the front shaft, if you have rzeppa's at the front shaft there should be no rips in the boots and no play or noise from it.
Check that and see whats happening.
1995 Jeep gc ltd, 2005 Jeep gc ltd , 71 Dart, 73 RR 440-6pk, 78 Mag GT, 85 Power Ram W-350, 92 Daytona, 99 Dakota, 08 Ram 2500
Less than 8 is like playing with half a deck
Long Island Motorsports Association