What is another name for a wheel hub?

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.

What does the wheel hub connect to?

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.

How does a wheel hub look?

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.

Is a wheel hub the same as a wheel bearing?

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.

Is a wheel hub the same as a rim?

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.

Does a wheel hub assembly include a bearing?

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.

How Long Do Drum Brakes Last?

HOW LONG DO DRUM BRAKES LAST ON A CAR

Drum brakes have two key components with very different service lives. Friction brake shoes typically wear out after about 30,000 to 40,000 miles, while the metal brake drums can last 150,000 to 200,000 miles and, in some cases, may last as long as the vehicle itself. However, actual service life varies depending on driving habits, vehicle load, road conditions, and maintenance.

How Long Do Rear Drum Brakes Last?

Brake Shoes

The friction material on brake shoes is the main wear component. As a general rule, brake shoes may need replacement around 30,000 miles, depending on driving conditions and maintenance. Excessive wear can reduce braking performance and allow the backing metal to contact the brake drum.

Brake Drums

Brake drums are generally more durable than brake shoes because they are made from thick metal and wear more slowly. They commonly last around 150,000 to 200,000 miles and may last the lifetime of the vehicle under favorable conditions. Many passenger vehicles use drum brakes on the rear wheels, where braking demands are generally lower.

How To Check Drum Brakes

Learn how to check drum brakes step by step, including brake shoes, drums, wheel cylinders, springs, and self-adjusters. Identify wear, damage, and leaks before replacement is needed.

Read the Complete Guide

How to Tell If Your Drum Brakes Need Replacing: Bad Brake Drum Symptoms

Strange noises when braking

A squealing or squeaking noise can be caused by worn friction material, but it may also result from vibration, dust, glazing, or other brake components. A grinding or scraping sound is more serious and may indicate that the brake shoe lining has worn through, allowing the metal backing to contact the drum. Continued metal-to-metal contact can damage the drum and may require machining or replacement.

A soft or spongy brake pedal

A soft or spongy pedal is more commonly associated with problems in the hydraulic brake system, such as air in the brake lines or a fluid leak. A leaking wheel cylinder can also affect brake performance. This symptom alone does not mean that the brake shoes or drum are worn and should be inspected to determine the cause.

A low brake pedal

If the pedal travels farther than usual before the brakes engage, it may be related to excessive clearance between the brake shoes and drum, an adjustment problem, or a hydraulic fault. Because several problems can cause a low pedal, the brake system should be inspected rather than assuming that worn shoes are the cause.

Vibration or pulsation

A drum that is out of round or has an uneven braking surface can cause the brake shoes to make inconsistent contact with the drum. This may be felt as a pulsating brake pedal or vibration during braking. Other brake components can also cause similar symptoms, so the drum should be inspected before replacement.

The car pulls to one side

If the vehicle pulls to one side during braking, the braking force may be uneven between the two sides. Possible causes include uneven brake shoe wear, a sticking wheel cylinder, contaminated friction material, incorrect adjustment, or other brake problems. The drum may be involved, but pulling alone does not confirm that the drum is defective.

A loose parking brake

If the parking brake no longer holds the vehicle securely or requires excessive travel, the cause may be worn brake shoes, cable adjustment, or another problem in the rear brake assembly. If repeated cable adjustment is needed, the brake system should be inspected rather than simply tightening the cable again.

Longer stopping distances

Increased stopping distance can be a sign of reduced braking performance. Worn friction material, oil or grease contamination, damaged brake components, or other brake system problems may contribute to the issue. If the vehicle takes noticeably longer to stop than normal, have the braking system inspected as soon as possible.

FAQs

Watch for three things. First, the warning signs: squealing or grinding noises, a soft or low brake pedal, vibration or pulsation when braking, the car pulling to one side, a loose parking brake, or longer stopping distances.
Second, the measurements: brake shoe lining thickness should be compared with the minimum thickness specified by the vehicle manufacturer. As a general reference, brake shoes may last around 30,000 miles, while brake drums can last 100,000 to 150,000 miles or longer, depending on driving conditions, vehicle load, and maintenance.
Third, a visual check: with the drum removed, look for brake linings that have reached their minimum thickness, a deeply grooved or out-of-round drum, leaking wheel cylinders, or broken springs and hardware. These conditions may indicate that one or more components need to be replaced.
If you notice any of these signs, have the brakes inspected. Identifying worn brake shoes early can help prevent further damage to the drum and avoid more expensive repairs.

With the drum removed, worn or damaged drum brakes may show several visible signs. The brake shoe linings may look thin, with little friction material remaining on the shoe. For riveted brake shoes, the lining should not be worn down to the rivet heads. The lining may also show uneven wear or contamination from oil or grease.
The drum’s inner braking surface may have grooves, deep scoring, hard spots, heat checking, or other signs of heat damage. An out-of-round drum may not rotate evenly and can cause uneven contact with the brake shoes.
You may also see dampness or brake fluid around the wheel cylinders, indicating a possible leak, as well as heavy rust or broken and loose springs and hardware. Any of these signs may indicate that the affected components need servicing or replacement.

Replace the drum when its measured inside diameter reaches the maximum allowable diameter specified by the manufacturer.

Check for common signs such as reduced braking performance, unusual noises, vibration, uneven braking, or excessive parking brake travel. For a more accurate assessment, inspect the brake shoes and drum and compare their condition and measurements with the vehicle manufacturer’s specifications.