Are your wheel bearings becoming unbearable? Don't worry, here's a handy guide to teach you all you need to know

If your car is making a rumbling or grinding noise, the steering is wobbling or your tyres are wearing unevenly, it’s likely that a wheel bearing is to blame. The good news is that it is a relatively cheap and easy fix for a garage, or can even be a DIY job if you know what you’re doing.

What are wheel bearings?

Firstly, let’s explain what wheel bearings are. They are an essential part of any vehicle, from a wheelbarrow to a juggernaut. They help a car roll along the road with as little friction as possible, thus saving fuel, reducing wear and increasing performance.

Wheel bearings work by encasing hardened ball bearings or rollers in between two metal rings. The mechanism is then packed with grease to protect the parts from wear. The driveshaft or a hub holding the wheel is attached to one side, allowing it to spin freely with as little friction as possible. 

What causes wheel bearing noise?

Over time these bearings can become loose or worn. This wear will be accelerated if the grease has leaked out or dirt, grit or water have found their way inside.

The first time you may know you have a problem is at a service or MoT test. Modern cars are good at insulating noise, and as the problem tends to build up over time rather than be a sudden failure, it can be difficult for a driver to detect.

If you can hear it, the noise is likely to be a grating, grinding or rumbling which changes with the road speed and doesn’t change when you blip the throttle or dip the clutch.

You may also notice a clicking noise and perhaps a vibration through the steering wheel, caused because the worn bearing allows the wheel to wobble. If you are at this stage, it’s really time to get it fixed as it will affect the handling of the car.

To do a DIY diagnosis, you’ll need to jack the car up and spin the wheels individually to see which one is noisy. It’s also worth rocking the wheel from side to side and up and down to check for clonks and movement.

How to fix wheel bearing problems

If you want to attempt a fix on a noisy wheel bearing yourself, check a workshop manual or online guide for instructions. You may find you can just pack the existing bearing with grease and tighten it up, especially on older cars. If you need to replace parts, think carefully before you attempt it yourself as you’ll need some pretty serious tools to undo seized nuts and press out the bearing. 

It’s also worth comparing the prices of a wheel bearing kit and a complete hub assembly. It might be that the time and effort needed to remove and replace the bearings alone means it will make more sense to swap the whole hub - especially if you are paying for a mechanic’s labour time. 

The price of parts will depend on all sorts of factors, but you might be pleasantly surprised as the same bearings might be used across many different cars. Online suppliers are likely to be cheaper than a dealer or motor factor, but make sure they’re reputable as fake branded car components are worryingly common. Also make sure you are ordering the right part – there can be a bewildering array of bearings, with differences existing even across the same model and production year of car.

If you are struggling to find the right part – for example with a classic or specialist car – it will be worth checking a directory to see if there is a bearing supplier near to you. These businesses will usually have a counter where an expert will be able to identify a part by sight – and they’ll be cheap too. 

However you fix them, it’s essential to get your bearings repaired if they are noisy or worn. If you just turn up the radio and ignore the rumbling they will damage and wear other, more expensive components, burn more fuel, and could even be a safety issue.