Wheel Bearing & Hub Assemblies

What is a Hub Assembly?  

Wheel bearings and hubs are parts of your vehicle’s steering, suspension, and braking systems.  A one-piece hub assembly incorporates the hub, wheel bearing, ABS wheel speed sensor, and mounting flange.

Wheel hubs connect the axles, steering knuckles, and the wheels and support the vehicle’s weight and turns the wheels.  Wheel hubs have a fixed part, the mounting flange, that mounts to and turns with the steering knuckle along with a revolving part (wheel bearings) which contain the lug bolts; they hold the wheel and brake rotor to the wheel bearing.

The axle fits into the bearing.  In front wheel drive, or 4WD car, when your axle turns, it turns the bearing, which turns the moving part of your hub.  The wheel and brake rotor held to the hub by lug bolts, turns with the hub allowing you to speed up or slow your car’s wheels.  In a rear wheel drive car, the front wheel bearing allows the wheel to turn freely. 

Front Wheel Bearing

Connect your front axles to your front wheels, helping the axles turn the wheels. Situated in the center of the hub, filled with grease and sealed with rubber, they have inner and outer rings, called “races,” and ball bearings between the two races.   

Rear Wheel Bearing Replacement

Rear wheel hubs connect rear axles to the brakes and the wheels.  Unlike front wheel hubs, they do not play a role in steering.  Rear wheel drive and 4WD connect the axles to the wheels to send power to the rear wheels.  Trucks don’t use separate hubs, they have solid rear axles that the wheels mounts to.  

When Wheel Hub Replacement is Necessary

It’s time to replace a wheel hub bearing when it’s making noise, or worse, affecting your steering or ride.  It’s the wheel bearing that leads to hub replacement.  Since wheel hubs made of solid steel, they rarely experience problems.

Wheel bearings fail because of age, dirt, water contamination, or improper installation.  Wear on the bearing’s rubber seals lets dirt and water in, quickening wear on the ball bearings or “races” making the bearings turn unevenly.  That uneven turning presents itself as a grinding noise, the noise gets worse as the car goes faster or when you turn.  If left, a worn bearing will give the sense that your steering is sloppy or cause “play” in your steering wheel. 

Wheel bearing and hub assemblies need replacement when the ABS sensor built into the hub stops working.  When this happens, the entire front wheel hub and bearing assembly needs to be replaced even if the hub was perfect.

Why Are My Wheels Vibrating? 

Your wheels vibrate when the wheel or ball bearings get worn, the axle turns unevenly and the wheels vibrate.  It feels like driving over a rumble strip with the vibration getting worse as speed increases or you turn.

How Much Does a Wheel Hub Replacement Cost? 

Wheel hub replacement costs vary based on the car model and who does the work; an independent mechanic or the dealership.  The cost for the hub itself ranges from around $100 to as high as $600.  Labor costs might range from about $150 to about $400. 

Can I Replace a Wheel Bearing or Wheel Hub Myself?

Replacing wheel hubs and especially wheel bearings is a job that requires some automotive experience.  If you have never replaced a wheel hub bearing assembly before, a service manual for your vehicle is useful. Front hubs can be difficult to remove because this area is prone to rust.  Use plenty of rust penetrating oil, and patience. 

Pressing in a wheel bearing is a precision job that can call for specialty tools.  If you need to press on a bearing, rather than installing a complete hub assembly, it’s best to have a professional do the work. 

General Overview to replace a typical Wheel Bearing Hub Assembly

1. Raise your vehicle and support it on jack stands.
2. Remove lug nuts and pull off the wheel.
3. Remove the brake caliper.  Tip: Hang it from the frame with zip ties or a bungee cord to avoid putting strain on the brake lines.
4. Remove the brake caliper bracket.
5. Pull off the brake rotor.
6. Remove axle nut.  A breaker bar is handy for this step
7. Remove bolts that hold the hub to the steering knuckle.
8. Pull old hub off. 
9. Lift the new hub into place and thread the bolts by hand.
10. Tighten the hub bolts to your vehicle manufacturer’s recommended torque setting with a torque wrench.
11. Fasten axle nut to the axle and tighten it to the recommended torque setting.
12. Slide on the brake rotor.
13. Put on the brake caliper bracket, install caliper bracket bolts and tighten to the recommended torque setting.
14. Put on the brake caliper.  Install the caliper bolts and tighten them to the recommended torque setting.
15. Slide on the wheel and thread the lug nuts by hand.
16. Lower the vehicle to the ground.
17. Tighten the lug nuts to the recommended torque setting.  

For in-depth information on wheel bearing and hub assemblies, such as how they work together, why they fail, replacement tips, and more, check out our  wheel bearings and hubs guide.