Your cars wheel bearing assembly (also called wheel hub bearing or wheel hub unit) is located between the brake discs and the drive axle. It contains the bearings that are responsible for the smooth movement of the wheels. A damaged wheel bearing assembly interferes with steering. Here are three common signs of a damaged wheel hub unit:
Watch out for rumbling, chirping, cyclic, or growling noises emanating from the area around the wheels. Your suspicion of wheel bearing damage should be confirmed if the noises are intermittent, change at high/low speed or when cornering. Don't confuse wheel bearing noise with transmission related noises; the latter change when you accelerate, decelerate, or coast.
The noises are usually generated by worn out bearings with worn out surfaces. Such bearings may have hairline cracks, indentations, or just roughened surfaces. Don't forget to have the bearing hub inspected too; it is possible that it is the part that is damaged was causing the noise. Replace damaged bearings because they can lead to loss of the affected wheel while driving, which can be dangerous.
To differentiate wheel noises from other noises, jack up the car, rotate the tire with your hands, and listen to its sounds. Any sounds emanating from the wheel bearing region is a bad sign, especially if it is coupled with rough movement of the tire.
Some level of wheel bearing play is normal and expected; otherwise, the bearing hub will be too tight, and the wheel's movement will be curbed. On the other hand, too much play is not good too because it leads to a wondering steering system.
How do you test for bearing play? Jack up the car, grab the wheel at the bottom and top, and attempt to rock it. The movement should be very tiny, almost imperceptible. If it is too much, then your wheel bearing needs to be serviced by a mechanic. For sealed bearings, you have no option but to get a replacement. For the adjustable type, a thorough inspection, cleaning followed by an adjustment may suffice.
An ABS light is one of the most obvious ways of knowing that there is a problem with your sealed wheel hub system. Of course, this is only applicable if your car's hub assembly is fitted with an ABS sensor. Note that the light may also come on due to faulty wiring or loose connections. Therefore, have your mechanic, one like Foster's Auto Service Inc, diagnose the root of the problem before replacing the hub assembly.
19 February 2015