What are the signs of wheel hub bearing failure?
The first signs of a worn wheel bearing are grinding, knocking, rattling, and other unusual sounds coming from the wheel. These sounds can get louder or disappear when turning corners. For example, noise when turning right indicates the problem of the component on the left wheel. Disappearing of the noise indicates a faulty bearing on the right side. In addition, vibrations can be felt on the steering wheel. Sometimes the vibrations are transmitted to the car body. When driving with a seized bearing, the car may pull to one side. If you grasp the top and bottom of the wheel and try to rock it up and down, there will be play.
In some cases the ABS dashboard warning light goes on, as the bearing and anti-lock braking system are interconnected: the component has an integrated ABS tone ring which is used for measuring the wheel rotation speed.
A common belief that a faulty wheel bearing may lead to incorrect operation of the drivetrain is baseless. So if your gearbox is malfunctioning, you should search for other causes of the trouble.
Can I change a wheel bearing myself?
If you have basic car repair skills, you can replace the wheel hub bearing yourself. Video tutorials from AUTODOC Club will help you with this. But keep in mind that the replacement process is quite labour-intensive. You may need a metal brush, a set of bearing drivers, spanners including a lug wrench, a hammer, and screwdrivers. It’s also a good idea to stock up on car care products: brake cleaner to remove dirt and degrease surfaces, penetrating oil to loosen stuck fasteners, and multi-purpose grease. If you have access to a car lift, it would make the job easier. On the average, replacement of the component on one wheel may take 1–3 hours, depending on the vehicle design and your skills.
The components needn’t be replaced in pairs on an axle. If necessary, you may replace only one faulty part. Usually, modern cars use wheel bearings made as one-piece units. There is no need to lubricate them before installation, as they are filled with a proper grease at the factory.
It is very important to tighten the wheel hub nut to a correct torque, otherwise the part may break down soon. The tightening torque varies depending on the car make and model and is usually specified by the vehicle manufacturer in the car service manual.
Is it dangerous to drive with a worn hub bearing?
Very. In the best case, driving with a bad bearing will end up with a costly repair of the suspension. In the worst case, if a hub bearing breaks while you’re driving, the wheel may jam, causing you to lose control of the car completely, which may result in a road accident.
How fast can a wheel bearing break down?
An average working lifespan of the component is 100.000–150.000 kilometres. However, in some cases, for example, if the part is defective or of poor quality, or if it was incorrectly installed, the bearing may break down even in 3.000 km.
Early breakdown of the component is contributed to by its misalignment from the rotation axis, overtightened wheel hub nut, use of impact tools for mounting, re-use of old fasteners and seals, and aggressive driving style with frequent abrupt starts and stops. Driving on rough roads and overloading the vehicle also adversely affect the part. It is not advisable to drive through deep puddles. Also you should avoid unprofessional tuning, as installing too wide or large-diameter wheels, use of low-profile tyres, stiffer springs and shock absorbers increase the loads onto the wheel hub assembly and can cause its fast destruction.