What do wheel bearings work in a car?

Wheel bearings are low maintenance parts, but that doesn’t mean they last forever. So, what does a wheel bearing actually do? How long does it last? And how can you help extend its lifespan?

What is a wheel bearing? And what does it do in a car?

A wheel bearing is a crucial part of the wheel assembly that connects the wheel and the axle. It is a set of steel balls (ball bearings) or tapers (tapered bearings), held together by a metal ring. It enables the wheel to rotate smoothly with a minimum of friction. Wheel bearings are safety critical components designed to sustain radial and axial loads caused by gravitation, acceleration, breaking & cornering forces, so they need to be replaced when they stop working properly.

How long does a wheel bearing last?

Wheel bearings have an average lifespan of 136,000 to 160,000 km (approximately 85,000 to 100,000 miles). This is only a rule of thumb though, the actual lifespan of a wheel bearing depends on the quality of the wheel bearing and the operating conditions.

What are the symptoms of bad wheel bearings?

The symptoms of bad wheel bearings include:

Noise:

A humming, rumbling or growling noise that increases with acceleration or as the vehicle turns.

A loud constant whining or grinding noise when the vehicle is in motion.

Clunking noises when driving over uneven road surfaces.

Looseness, excessive play in the steering wheel (vague steering);

Steering wheel vibration which changes with the vehicle speed or as the vehicle turns;

ABS malfunctioning. ABS system issues can be related to failure of the ABS sensor that is integrated in the wheel end bearing. 

What are the risks of driving with bad wheel bearings?

It's very rare for wheel bearings to fail immediately and completely after you notice the first symptom(s). 

Having said that, it is best to avoid driving with a worn wheel bearing for any length of time. As we’ve already seen, the wheel bearing is essential for connecting your wheel to your car, and any weakness in this connection could have severe consequences for your drive-axle and steering assembly – as well as for your safety.

Replacing your wheel bearings

Despite the fact that modern wheel bearings are easier to install than previous generations, correct installation, the usage of appropriate tools and respecting the specified torque values are still essential for maximum performance, durability and safety. Therefore, we recommend having your wheel bearings fitted by a professional mechanic that has the skills and the tools to do the job.