2002 Honda CRV wheeels?

Steering vibrates when 40 or more worse as faster.

grinding sound is constant on moving does not get worse or louder, but on sharp left or right makes another clunk sound (single)

Bought car used from dealership
They have changed the tires (owner had unmatched tires on car) re cut rotors 3 times. Wheels do not hold balance mechanic stated that he does not know why, they have been balanced 5 or 6 times.
when on lift at my mechanic to see where sound came from, I saw left rear wheel in eliptical spin. Not round.
sound comes from rear near wheel.