Wheel Bearing Diagnosis
Wheel bearings make a growling or grinding sound when worn. To diagnose whether the noise is caused by 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.
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 faulty bearing is usually on the side opposite of the turn. This is because when the vehicle is turned left, more of the vehicle’s weight is transferred 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 and cupping.
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 inspecting for looseness and wear.