My '05 RTV's ujoints ,when going out,made a click and it had a slight hesitation when moving from a stopped position. This was the cracked u joint slack making the hesitating movement. I would also check the lug nuts and just make sure they aren't loose. You might have a dry bearing in the wheel too. I would just jack the rear up off the ground,and do an inspection... turning , twisting, and looking for anything moving that shouldn't. There is also a "crown" nut that fits on the end of the axle shaft and has a cotter pin going through the "castles" ,it keeps the nut from moving.. Make sure it isn't loose. Good Luck ! collie.