How can you tell the difference between a flat spot on the tire and a bad wheel bearing?

If you suspect a flat spot on a tire examine the tire closely. You should be able to see a flat spot.

To determine if your car has a bad wheel bearing rotate the wheel. A bad wheel bearing will often make a grinding sound as well as feeling rough as you turn the wheel. A bad wheel bearing may also shake or wiggle. It will also cause a car shaking problem.