What’s Making That Awful Noise? – Is it Bad Brakes Or the Wheel Bearing?

A big part of running a good shop is identifying issues as quickly and efficiently as possible. Some issues can be hard to identify, though. For example, it can be challenging to identify the issue that’s causing strange noises from a wheel. The most common issues that cause strange wheel noises include:

• Worn tires
• Worn or damaged wheel bearing
• Bad brakes

It’s pretty easy to inspect the tires for any issues. It can be hard to figure out whether bad brakes or a bad wheel bearing is causing the noise, though. This guide will help your technicians determine the issue as quickly and efficiently as possible.

Noises Caused By Bad Brakes

What do bad brakes sound like? There are several different ways bad brakes can cause noise. Here are the most common causes:

• Grinding caused by:
  • The backing plates on worn brake pads grind against the rotors as the brakes are applied.
  • A stuck caliper or wheel cylinder can keep the brake pads pressed against the rotor, even when the brakes aren’t applied.
  • Foreign debris stuck in the brake system
• Squealing or squeaking caused by:
  • Some brake pads come with a metal wear indicator that drags against the rotor when the pads are worn.
  • Glazed rotors or drums
• Clattering or rattling caused by:
  • When a rotor or drum gets warped, contact with the pads or shoes is uneven.
  • Damaged, loose, or missing hardware

Noises Caused By A Bad Wheel Bearing

Wheel bearings usually take a long time to wear out. Sometimes they fail early, though, from:

• Impacts (pothole, curb, etc.)
• Contamination (water, dirt, debris)
• Improper alignment

A worn or damaged wheel bearing is quite noisy. So when a wheel bearing goes bad, you’ll notice some noise. Bad wheel bearings usually cause the following noises:

• Knocking or clunking caused by extra stress on the CV-joint
• Crackling caused by:
  • A worn or damaged outer CV-joint
  • Excessive bearing endplay due to poor clamping
• Rumbling or growling caused by the bearing’s inability to turn as freely anymore
• Grinding caused by bearing roller or raceway damage

What To Look For When Test Driving The Vehicle

Image Credit: CarAndDriver

The best way to determine the cause of the strange wheel noise is to lift the vehicle and then inspect the tires, wheel bearings, and brake assembly. Yet, it’s quite time consuming. Sometimes you can figure out the cause of the noise simply by taking the vehicle out on a test drive.

Here are four key things you should look for on a test drive:

1. The Type Of Noise

Listen carefully and see if you can identify the noise. The type of noise will give you a big clue on what the problem may be. The only noise a bad bearing and bad brakes have in common is grinding.

2. When The Noise Occurs

The timing of the noise is another big clue. If the noise occurs only when braking, the issue is obviously bad brakes. If the noise shows up after about 30 mph, chances are it’s a bad wheel bearing.

3. The Most Common Symptoms Of A Bad Wheel Bearing

When test driving a vehicle, look out for the following symptoms of a bad wheel bearing:

• Loose steering
• Vibration in the steering wheel
• Vehicle veering in a particular direction

4. The Most Common Symptoms Of Bad Brakes

When test driving a vehicle, look out for the following symptoms of bad brakes:

• Spongy or soft brake pedal
• Vehicle veering in a particular direction while braking
• Vibration in the brake pedal
• Slower stopping response

Still Not Sure Where The Noise Is Coming From?

If the test drive didn’t help you pinpoint the issue, lift the vehicle and:

1. Inspect the wheel bearing assembly for damage
2. Inspect the brake system (calipers, rotors, and brake pads)

Using Quality Replacement Parts

Whether the issue is a bad wheel bearing or bad brakes, be sure to use quality replacement parts. Using quality replacement parts comes with several benefits:

• It reduces comebacks.
• It keeps your customers safe on the road.
• It helps build your customers’ trust in your shop.

Here’s a good resource on finding a quality parts manufacturer. If you’re looking for high quality wheel bearing manufacturer, look no further than GMB. We manufacture OE-quality hub assemblies and wheel bearings. Learn more about our parts here!