A wheel bearing is a friction reduction device placed within the wheel to aid efficiency of rotation. The bearing rotates in conjunction with the wheels rotation, and this allows the wheel hub to rotate as freely as possible. Like most mechanical parts on a car, they tend to wear out and the tell-tale sign of this is noise coming from the affected wheel. The main causes of a faulty wheel bearing are:• The alignment is off.• Damaged or leaking bearing seal.• Inward collision due to a side impact.For more information on this product, drop us a message or use our registration lookup on the home page for specific technical details.