All About Mercedes-Benz Wheel Hub Assemblies and Bearings

What are They?

A wheel hub assembly goes by many names, whether it's up front or in the rear of your car or SUV. Some automakers refer to it as a wheel hub bearing or hub bearing assembly, while others simply call it a hub assembly. Others yet just say wheel hub unit or, more comprehensively, hub and bearing assembly.

Put simply, it's a unit comprised of bearings, seals, and sensors (like those for wheel speed). You'll find one per wheel in most Mercedes-Benz models made since 1998. Many of the brand's rear-wheel-drive vehicles, however -- those made before 1997 -- usually have two individual bearings and seals in each front wheel.

The ones you've got are probably located on each wheel. You'll find them between the drive axle and either the brake drums or brake discs, depending on what kind of braking system your vehicle has. Their bolts attach the wheels to the vehicle on the drum or disc side; otherwise, they're bolted on or pressed into the steering knuckle on the axle side. To get a better look at them, simply remove the wheel and then remove (in the case of disc brakes) the brake caliper and brake rotor.

A wheel bearing, you'll find as a set, in the center of the wheel hub, connecting the axles to both the front and rear wheels. In sum, both are important parts of your steering, anti-lock braking (ABS) and traction control (TCS) systems. Their job explains why.

What Do They Do?

They allow your Mercedes-Benz vehicle to turn freely and smoothly. This makes them critical to everything from turning and changing lanes reliably to simply driving straight. If they begin underperforming at this -- that is, if they begin deteriorating -- your wheels won't be able to turn as well, and they may become unstable. If the metals that make them up degrade, they can fracture, and your wheels can come off, putting you in serious danger during a drive.

What are the Signs and Symptoms They're Failing or Bad?

A bad wheel hub assembly has the following: growls, hums, squeaks, chirps, or squeals coming from your tires at low speeds; a shaky steering wheel; an ABS light on the dash (if your sensor is having trouble reading or sending a signal). Worn or bad bearings have the following: whirs, snapping sounds, or clicks as you drive.

If you're experiencing any of these, replacement is recommended as soon as possible. That means the hub assemblies on each front and rear wheel and their bearings, depending on what's at issue. You can order the parts you need for the project right here online.

Shop the Best Wheel Hubs and Bearings for Your Mercedes-Benz Online: Genuine OEM

The luxury brand you love manufactures them to spec for each of its cars and SUVs. That's tantamount to a fitment guarantee -- one the aftermarket can't always make. Our auto parts store has a complete catalog -- just browse by year, make, and model to find the right fit for what you drive. Buy now, and we'll ship quickly, right to your door, so you can take care of the job in no time.