There is a small amount of play top to bottom and left to right in my right rear tire. Not much, but more than on the left. With the car supported and the transmission turning the thumping is clearly comming from the outer axle joint/hub bearing area. With the axle out of the hub it seems fine (no looseness). I did not remove it from the differential. I would be more inclined to do the axles myself than the bearing so I talked to my mechanic about having him do the bearing. Without seeing my car, he said he was sure it was the axle and not the bearing since there had been no whirring sound. I dont wan't to put 2 new axles in and have it not solve the problem.
Thanks, John