It could be a break drum, rotor, or shoe. It could also be a bad tire. Sometimes they get a bulge, usually on the side you can't see.
Type your answer here... Rims bent
Possibly a bad wheel bearing.
The tire itself may be bad, with a flat spot (no tread) or bulge. Also, a wheel that is badly out of balance can thump at some speeds.
water/friction
Bad tire Bad wheel bearing Swap tires front to rear and see if problem changes Check wheel bearings for "play"
You should have someone pull off the hubs and check your bearings to see if they need to be replaced or just repacked
Flat spot on the wheel. Bad wheel bearing. (however its usually the front not the back) Rotate the wheels and see if the problem travels with the a certain wheel
you may have a low tire or your tires are to big
My left wheel ticking while driving was causes by brake pads that did not fit. As explained poor fit.
The whistling sound made by your car could be caused from brake dust. Another reason may be from a bad wheel bearing that needs to be replaced.
loose lugnut, wheel bearings, cv joint, u joint, bad tire(s), it could be many problems. i would start in the order mentioned and go from there. just dont go to a mechanic saying "i dont know what this noise is.." they are likely to soak you with more to spend.. hope that helps..
Sounds like a loose wheel But it could be a bad tire with a "Lump" in it. Both are very dangerous so you need to have your car checked and repaired.