A worn wheel bearing usually makes a humming, rumbling or growling noise that gets louder as your speed rises and changes when you go around a corner. It will not fix itself, and the longer it is left, the more play and heat build up in the hub, so it is worth getting checked as soon as you notice it.
The good news is that wheel bearing replacement is routine workshop work. Below we cover the symptoms, how to tell a bearing from other noises that sound similar, why it should not be left, and what affects the cost of replacing one. If you already know you have a noise, our CV joint, axle and wheel bearing repairs page explains how we diagnose and fix it.
What a wheel bearing does
Each wheel spins on a set of bearings inside the hub. They carry the weight of the car, take the loads from cornering and braking, and let the wheel turn smoothly at any speed. They are sealed and packed with grease, so on most modern vehicles they are not serviced. They simply run until they wear.
When a seal fails, water and grit get in, the grease breaks down and the bearing surfaces start to wear. That wear is what you hear.
Bad wheel bearing symptoms
The signs usually start quietly and build over weeks or months.
- A hum or growl that rises with speed. Often described as sounding like aggressive tyres or a plane in the distance. It gets louder the faster you go.
- A noise that changes on corners. Because cornering shifts weight onto the outside wheels, a worn bearing often gets louder when turning one way and quieter turning the other.
- Rumbling or vibration through the floor or steering wheel, especially at open-road speeds.
- Play in the wheel. In more advanced cases the wheel can be rocked by hand when the car is lifted.
- Uneven brake pad wear or a pulse under braking, because a loose bearing lets the rotor move slightly.
- An ABS or traction control light. On many modern cars the ABS sensor reads from the bearing, so a worn one can upset the signal. Our guide to the ABS warning light explains more.
Wheel bearing, CV joint or tyre noise?
These three get confused all the time, and they often sit right next to each other.
- Wheel bearing: a hum or growl that rises with speed and changes with cornering. It is usually there at a steady speed in a straight line too.
- CV joint: a clicking or knocking on tight, slow turns, like a roundabout or pulling into a car park. A clunk when you take up drive points to an inner joint. Our guide on driving with a bad CV joint covers this in more detail.
- Tyres: cupped, feathered or unevenly worn tyres can drone in a way that sounds very like a bearing. The noise often changes when the road surface changes. Worn shocks are a common cause of cupped tyres, so it is worth checking both.
A quick way people try to tell them apart is to change lanes gently at speed and listen for the noise to change. It is a useful clue, but the only certain answer comes from putting the car on a hoist, taking the wheels off and checking each bearing and joint directly. Guessing wrong means paying for a part that did not need replacing while the noise carries on.
Why you should not leave a noisy wheel bearing
A worn bearing does not stay the same. As it wears, play increases and the bearing runs hotter. Left long enough:
- Steering and braking can be affected, because the hub and rotor are no longer held firmly in place
- Nearby parts wear faster, including brake pads, rotors and the CV joint
- The ABS can stop working properly on cars where the sensor reads from the bearing
- In the worst case the bearing can seize or break up, which can be dangerous at speed
It can also catch you out on a WOF. Under the NZTA in-service WOF requirements, a wheel bearing is a reason for rejection if it has play beyond the manufacturer’s specifications, is over-tight or binding, or feels or sounds rough when rotated.
What wheel bearing replacement involves
Wheel bearings come in two main types, and which one your vehicle has changes the job.
- Bolt-on hub assemblies. The bearing comes as a complete hub unit that bolts onto the suspension. Many modern cars use this type.
- Pressed bearings. The bearing is pressed into the steering knuckle or hub carrier. The hub is removed, the old bearing pressed out and the new one pressed in.
At our Frankton workshop, the vehicle goes on the hoist and the wheels come off. We spin each bearing by hand to feel for roughness and check for play at the hub, and we look at the CV boots and brakes while we are there, because faults in this area often overlap. Once you approve the quote, the new bearing is fitted, torqued to the manufacturer’s specification, and the car is road tested to confirm the growl has gone.
What affects the cost of replacing a wheel bearing
We do not publish prices, because wheel bearing jobs vary a lot from one vehicle to the next. These are the main things that move the cost:
- Bearing type. A bolt-on hub assembly and a pressed bearing are different jobs, with different parts and labour.
- Front or rear. Front bearings on front-wheel drive cars sit behind the CV joint and steering parts. Rear bearings on some vehicles are simpler, on others not.
- Driven or non-driven wheel. A bearing on a wheel that also carries drive usually means more parts come off to reach it.
- Vehicle type. Utes, 4WDs and light commercials have heavier hubs and different setups from a small hatchback.
- Corrosion and seized parts. Older vehicles and those that see gravel roads, beaches or farm use can have seized hub nuts and bolts that take extra time.
- Integrated ABS sensor. On some vehicles the ABS sensor ring is part of the bearing or hub, which affects which part is needed.
- One side or both. If the other side is also worn, doing both at once can save on labour compared with two separate visits.
- Anything else found. If a CV boot is split or the brakes are due, it can make sense to sort them while the wheel is already off. We will always ask first.
What to ask for in a quote
A clear wheel bearing quote should tell you:
- Which bearing is worn, front or rear, left or right, and how it was confirmed
- What type of part is being fitted, a hub assembly or a pressed bearing
- Whether the other side was checked, and what condition it is in
- Whether anything else was found while the wheels were off, such as CV boots or brakes
We give free quotes, and nothing is done without your sign-off. If a repair is putting pressure on the budget, we are a WINZ-approved repairer and can prepare a free WINZ quote for Work and Income.
Get a wheel bearing noise checked in Hamilton
If you can hear a hum or growl that gets louder with speed, it is worth getting it diagnosed before it gets worse. Our MTA member workshop is at 281 Kahikatea Drive, Frankton, Hamilton. We will put the car on the hoist, find out whether it is a bearing, a CV joint or a tyre, and give you a free quote. Visit our CV joint, axle and wheel bearing repairs page or call us on (07) 847 3339 to book.