My 1992 Lumina Euro is making a loud clunking noise in the back right tire when I go over large bumps in the road. Most of the people I have talked to thinks it's a wheel bearing problem, but some doubt that. If I grab the wheel by the sides and rock it back and forth, the sound is generated...if I do this on any other wheel, it does not. Car milage is 63000. Any help will be appreciated.