Your car’s wheels and tires are the most visible part of the suspension system that helps your vehicle maneuver. However, the wheel bearings located within each hub perform much of the heavy lifting. As wheel bearings begin to wear, they exhibit signs – and sounds – of failure that become a safety risk to all occupants if not addressed promptly.
This guide explores the common causes of wheel bearing failure and eight key symptoms associated with a bad wheel bearing. If you notice any of these symptoms, you can use the included tests to verify a bad wheel bearing before scheduling repairs immediately. Identifix Direct-Hit® can help auto repair shop technicians reduce the time spent diagnosing wheel bearing failure and avoid misdiagnosing a bad wheel bearing as a brake or tire problem.
The Role of Wheel Bearings in Safe, Smooth Driving
Wheel bearings are an essential component in your vehicle’s suspension, steering, and brake systems. Each wheel requires a wheel bearing to:
A wheel bearing consists of a set of steel balls—bearings—held together in a cage. A sealed metal ring—the race—holds the cage and is packed full of a specific type of grease. The race fits inside the hub and rides on the metal axle shaft.
What Causes a Wheel Bearing to Fail?
For the most part, wheel bearings are a relatively low-maintenance component. However, wheel bearings must remain sealed to keep water and road dust out, as the only source of lubrication is the grease packed within them. Most wheel bearings last anywhere from 75,000 to 150,000 miles, depending on:
The cost of replacing wheel bearings varies based on the make, model, model year, bearing type and corresponding price, and labor. Most wheel bearings cost anywhere from under $100 to over $600. It’s best to replace wheel bearings instead of repairing them, but you don’t have to replace both sides unless they’re equally worn.
In the case of electric vehicles (EVs), the wheel bearings must bear greater weight due to the battery. While some auto manufacturers may design the new wheel bearings accordingly, any components borrowed from a gas-powered vehicle can wear out faster due to the excessive weight. Any of the causes of wheel bearing failure above can also exacerbate the problem.
More About Bad Wheel Bearings
If you want to delve further into bearing damage, Timken’s Bearing Damage Analysis Reference Guide features several informative explanations and visual examples of common types of damage. You can also reference ChrisFix’s “How to change a Wheel Bearing (short and fast version)” video.
8 Symptoms of a Bad Wheel Bearing
Don’t drive on a bad wheel bearing if you can avoid it. If you discover you have a bad wheel bearing while on the road, avoid turning rapidly and slow down cautiously before calling a tow truck. Below are the key symptoms of a bad wheel bearing, as identified by industry experts such as Timken.
1. Unusual Noises
Noises caused by a bad wheel bearing can sound similar to those that indicate a bad CV joint. Humming, clicking, howling, and popping can signal a faulty CV joint. Additional noises that are more characteristic of a bad wheel bearing include the following:
These peculiar noises typically occur when small metal pieces flake off the races within the wheel bearing and disperse through the packed grease. As they come into contact with other metal components, harsh noises occur. In advanced stages of wheel bearing failure, bearings may also click or pop, similar to a bad CV joint.
2. Loose Steering
It can be more challenging to notice changes in steering that indicate a bad wheel bearing. The steering may feel less responsive and precise when a wheel bearing goes out. Excessive play in the vehicle’s steering can also indicate it needs an alignment, but the play will typically be accompanied by the steering pulling to one side.
3. Uneven Tire Wear
Several factors contribute to scalloping, cupping, and other manifestations of uneven tire wear, including improper alignment, inadequate inflation pressures, and issues with key suspension components. A bad wheel bearing can also cause abnormal wear, as the bearing play allows for greater fluctuations in surface contact between the tire and the road. Rule out any other issues with suspension components or tire characteristics to diagnose a bad wheel bearing properly.
4. Inefficient Braking
Bad wheel bearings that introduce play into the wheel and tire can put undue pressure on the brake rotor. With enough abnormal preload from the wheel bearing, the rotor can push the brake caliper piston further, negatively affecting brake performance. At the brake pedal, it can feel as though the brakes aren’t responding as well as they should be.
5. ABS Light
With loose wheel bearings causing a loss of tight tolerances, the wheel and tire assembly can flex, transmitting vibrations that can trigger the Anti-lock Braking System (ABS) or traction control warning light. The brake rotors, calipers, and pads can also relay this movement and cause the same result. Bad wheel bearings that trigger an ABS light can be misdiagnosed as a faulty sensor.
6. Steering Wheel Vibrations
The same wheel bearing play that trips the ABS light can also cause vibrations in the steering wheel. Steering wheel feedback due to a faulty wheel bearing typically increases when turning and at higher speeds. However, steering column tremors can also be linked to worn tires or suspension components.
7. Wheel Wobble and Pulling
In extreme cases, enough wheel bearing play can cause the wheel and tire to wobble, pulling the vehicle in the same direction as the worn bearing. Warped brake rotors can also pull a car’s steering to one side or the other, but typically only when braking. If a vehicle’s suspension is out of alignment, it will also pull to the left or right.
8. Burning Smell
The grease packed within a wheel bearing helps reduce friction. However, when the grease begins to lose its lubricating properties, it can generate excessive heat due to increased friction. If you notice a burning, acrid, or plasticky smell, it could be caused by a wheel bearing that’s close to failing completely.
How to Confirm a Bad Wheel Bearing
The symptoms listed above can help you narrow down the source of any issues to one or more wheel bearings. However, additional testing will help you confirm the wheel bearing as the source, rather than the tires or braking system. Below are methods you can use to prove a bad wheel bearing:
Confirming a bad wheel bearing is step one of several aimed at reducing the risk of a wheel breaking off while driving down the road. If you believe your wheel bearings may be failing, replace them immediately to ensure your safety and that of your passengers.
Quick, Accurate Wheel Bearing Diagnosis with Identifix
Recognizing the signs of a bad wheel bearing can help you diagnose the problem before you lose any wheels. In addition, routine maintenance and annual inspections can help keep your car’s wheel bearings in proper working order. Contact us to learn more about how you can use Identifix Direct-Hit and Direct-Hit Mobile to simplify repairs.
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