Wheel bearings allow wheels to rotate.

Each wheel bearing includes rollers that support the weight of the car on the axles when turning. The price of the parts and labor to replace a wheel bearing at a mechanic's shop runs about $250 to $300 per wheel.

1,Check for uneven tire wear. If a wheel bearing is bad, more weight will be put on other wheels, causing uneven wear.

2,Jack up suspected loose wheels. Shake the wheel. There should be little to no movement. If there is movement, the wheel bearing could be bad.

3,Listen for noise coming from the wheels. If the noise--a grinding or humming sound--goes away when the car turns, then the problem is the front wheel bearings. If the sound does not go away, the rear wheel bearings are bad.

4,Look in your service journal to see the last time your wheel bearings were changed. Bearings should be changed every 30,000 miles. If you have consistently lubricated them every 2 to 3 thousand miles, they could last 100,000 miles.