Wheel Bearing Diagnosis
Wheel bearings make a growling or grinding sound when worn. To diagnose whether the noise coming from a worn wheel bearing, a brake unit or something else, a dry and quiet surface is best suited. You need to be able to hear the bearing.
Road Testing a Wheel Bearing
Notice if the sound goes away or changes pitch while turning. If the noise is most affected during left-hand turns, suspect a faulty right side bearing. The defective bearing is usually on the side opposite of the turn. When a vehicle is turned left, more of the vehicle’s weight transfers to the right front wheel and vice versa.
When the sound changes pitch when driven on different surfaces, and is not affected during turns, look at the tire tread for aggressive patterns or cupping.
Diagnosing Sealed Wheel Bearings
Raise the vehicle and check the bearings by grasping the tire at the twelve and six o’clock positions, and then rocking the wheel back and forth. Excess movement indicates a worn wheel bearing. Rock the tire back and forth at the three and nine o’clock positions and inspect the steering rack, suspension components, and linkage for looseness. Have a helper turn the steering wheel while checking for looseness and wear.