i rotated my tires like gm says to and now the back end bounces around

a hole lot and it sounds like the wheel is moving on the studs or

something. the rims are aftermarket and they came with indexing rings to

make the new lugnuts tighten up on the studs. the lugs are tight and im

gonna check to see if the ring is still on there tomorrow. My 1st question

is should i rebalance the wheels after rotation probably need it anyway

b/c i hit a big pot whole with the drivers side front so hard i made the cd

skip in the cd player. 2nd question is when can you tell when you need

new tires. the ones of the front are pretty worn down and i think the need

replacing becasue of the lil marker in between the tread.