Are you expierencing torque steer? If you accelerate, does it pull to one side & pull to the other when you let off the gas to shift?
I'm fighting this problem right now, still trying to track it down. First thing to do is visually inspect everything under the Jeep. Check the U bolts on the rear end, check the spring shackels,check the body mounts, make sure everything is still torqued down.