Question 1

What is another name for a wheel hub?

Accepted Answer

Common alternative terms for a wheel hub include "hub" and, in automotive repair and parts sales, sometimes "wheel hub assembly." However, strictly speaking, a wheel hub and a wheel hub assembly are not exactly the same thing. Likewise, a wheel bearing should not be used as an exact synonym for a wheel hub.

Question 2

What does the wheel hub connect to?

Accepted Answer

The wheel hub primarily connects the wheel to the vehicle's braking, suspension, and axle-related components. The wheel and, typically, the brake rotor or drum are mounted to the hub. The hub is supported by the wheel bearing, allowing it to rotate relative to the steering knuckle, axle, or other supporting components. On driven wheels, the hub also connects to the half shaft through splines to transfer driving torque to the wheel.

Question 3

How does a wheel hub look?

Accepted Answer

A wheel hub is typically a round, disc-shaped metal component with a central section, located at the center of the wheel. It usually features a hub flange for mounting the wheel and brake rotor or drum, with wheel studs or wheel bolt holes arranged around the flange. The center may include a bearing mounting surface or bore and, on driven wheels, splines for connecting to the half shaft. Modern wheel hub assemblies are typically thicker and more complex because they may also incorporate the wheel bearing, an ABS wheel speed sensor, or a magnetic encoder.

Question 4

Is a wheel hub the same as a wheel bearing?

Accepted Answer

No. The wheel hub and wheel bearing serve different functions. The wheel hub is a structural mounting component that connects the wheel to the vehicle, while the wheel bearing supports the hub and allows the wheel to rotate smoothly. Serviceable bearings may be removed, cleaned, repacked with grease, and adjusted, while bearings integrated into a wheel hub assembly are typically replaced as part of the entire assembly.

Question 5

Is a wheel hub the same as a rim?

Accepted Answer

No. The rim is the outer part of the wheel that supports the tire, while the wheel hub is the central mounting component that connects the wheel to the vehicle. The wheel mounts to the hub, and the brake rotor or drum is also typically mounted to the hub. The rim and wheel hub are therefore different components.

Question 6

Does a wheel hub assembly include a bearing?

Accepted Answer

Yes. A wheel hub assembly typically includes a wheel bearing as part of a preassembled unit. Depending on the design, the assembly may also include the hub flange, wheel studs or wheel bolt holes, an ABS wheel speed sensor or sensor provision, and a tone ring, reluctor ring, or magnetic encoder. The bearing is typically sealed to help protect it from water, dirt, and road debris.