What is a wheel bearing?
A wheel bearing is an un-sprung component of a vehicle suspension that is designed to negate the effects of a wheel in motion with friction. A wheel bearing is located at each wheel hub where the car wheel/tire assemblies are located.
How does it break?
As a general rule, wheel bearing failure can occur from general wear and tear throughout a vehicle’s life. In vintage cars, wheel bearings are serviced regularly with automotive grease and a replacement seal so when maintenance is foregone failure will occur. But in modern vehicles the wheel bearings are sealed permanently and are not serviced. They are replaced only when their failure is discovered. However, this does not guarantee that a wheel bearing will never fail. There are many reasons for a wheel bearing failure which is not limited to overloading, collision impacts, and extended mileage.
How do I know it needs to be replaced?
When the vehicle is in motion, you may here a growling noise that coincides with the rotation of the tires. Also, you may feel a vibration in the steering in the case of the front and in the vehicle seat or floor in case of the rear. That is what usually alerts the driver to a wheel bearing issue. When steering and changing lanes on the roadway, sometimes a change in growling pitch and vibration might be noticed and will alert the driver to a bearing issue as well. In severe cases, a low brake pedal will be due to a wheel bearing issue.
How much does it cost and why?
The cost of a front wheel bearing replacement varies greatly among vehicle applications. Typically an estimate on a front wheel bearing repair for a domestic front wheel drive car will be from $250 to $400.
Asian imports in the years of 1980s to early 2000s would be pricier at $300 to $400 because of a two piece hub and bearing design that will require higher part and labor costs. Modern rear wheel drive light trucks carry a price of a front wheel bearing replacement of $300 to $400. European imports generally will estimate at a $400 — $600 replacement cost because of parts costs being higher.
Rear wheel bearing replacements are a different story. Front wheel drive vehicles have rear bearings that are not connected to the axle and drivetrain mechanism. They are easily replaced as a bolt on assembly and estimate at $100 — $200 in most applications. Rear wheel drive vehicles such as light trucks have wheel bearings that are pressed fit to the rear axle housing or on to the axle themselves.
Repairs on rear wheel drive bearings require more extensive labor time because of extra steps that are involved in the process. Many Toyota and Nissan light trucks can estimate out at over $1,000–1,200 for rear axle bearing replacements.
What happens if I don’t replace it?
Ignoring wheel bearing issues can affect braking performance. A low brake pedal feel is caused by a misalignment of the brake rotor to the brake caliper when severe failure is imminent. Also a potential loss of steering control can develop if faulty wheel bearings are not replaced because a change in vehicle camber and toe will cause unstable tracking and handling when driving. Finally, in some extreme cases, a bad wheel bearing can cause the wheel/tire assembly to come off of the vehicle, potentially leading to an accident.
Is it different for different cars?
Essentially, the symptoms are universal to most all vehicles. The only difference would be variability in repair costs.
Can I replace it by myself?
Generally, front wheel bearings are replaced as a hub/bearing assembly meaning no extra parts will be necessary. Only if extended use has damaged the brakes a replacement of pads and rotors may be needed. However, in the case of rear wheel bearings, there are many other variables that can be uncovered after inspection. Rear brake pads/linings can be contaminated with axle lubricant. Rear axle bearing housings, races, seals, axle fluid, and axles themselves may become casualties too. A proper inspection will uncover any further cost issues regarding rear wheel bearings.
Are there any ways to save on cost?
With some applications, a bargained price wheel hub/bearing may available from auto parts discounters. But remember that a shorter part warranty time period may accompany it and generally it is not recommended to take that route. The best way to make a wheel bearing repair cost less is to have the vehicle serviced and inspected on a regular time and mileage schedule so that potential wheel bearing issues can be discovered before the costs get too catastrophic.