If you’ve ever wondered how a wheel spins independent to the rest of the car, the wheel bearing is your answer. A wheel bearing allows the non-driven wheels to spin as fast or as slow as the driven wheels like. Allowing the car to go as fast or as slow as it wants thanks to the bearings in the driven wheels, with almost no resistance from the non-driven wheels.

What is a wheel bearing?

Typically located inside the wheel hub assembly, a wheel bearing is a circular metal wheel which encases either ball bearings or roller bearings around the inside of the outer wheel. On the inside of those bearings is another wheel which is what is fitted to the input of the car wheel. This means that as the wheel spins the inner bearing wheel, the ball or roller bearings allow it to rotate without spinning the outer wheel which is fitted to the hub.

Why do you need a wheel bearing?

Not only does it make it possible for your car to drive down the road, you also need them all in perfect working condition to get a WoF. If they aren’t then you can fail your warrant of fitness. So you need them to drive your car and you need them to legally drive your car too.

How do you know when it is time to replace your wheel bearing?

You may notice that your car pulls in one direction while driving down the road. Other key signs are that you can hear a distinctive low rumbling sound that gets louder the faster you go. You may also feel the steering wheel pull or bump as you drive down the road. 

What happens during a wheel bearing replacement?

It’s a niggly little job, especially without a press, which is why it’s best left to a mechanic. They will first identify the faulty bearing by doing a simple spin check, they will then unbolt the wheel and remove the wheel hub assembly. The old bearing will be pressed out of the hub using a hydraulic press. The bearing mounting surface will be cleaned and a new bearing pressed in. The hub assembly is then good to be refitted to the car and will be bolted back on. The wheel will then be bolted back on too and a quick test performed to check that everything is working properly.

How much does a wheel bearing replacement cost?

It really varies based on the type of bearing and how many need replacing. A simple, single job will probably be around $200 but for two or more bearings that require pressing and fitting it can quickly climb over $500 and above.

How often do you need a wheel bearing replaced?

Most modern cars come with sophisticated modern bearings. They will only need replacing if something goes wrong. Older bearings that require servicing typically last around 150,000km

Is driving with a broken wheel bearing unsafe?

If your wheel bearing fails and is unable to perform its job then it can be very dangerous indeed. Most of the time they fail progressively - not at once. So if you feel a bearing start to fail then you need it replaced as soon as possible.