Hearing a strange noise from your car’s wheels can be worrying. You might be wondering why wheel bearings fail and how to tell which wheel bearing is bad. This guide will walk you through the signs, causes, and the next steps you should take to get it fixed safely.
Why Wheel Bearings Fail: How To Tell Which Wheel Bearing Is Bad & Next Steps – The Tire Reviews
A wheel bearing is a crucial set of steel balls or tapers held within a metal ring. It allows your wheel to spin smoothly with minimal friction. When it’s in good shape, you don’t even notice it’s there. But when it starts to fail, it can’t support the weight and speed of your vehicle properly, leading to serious problems.
Common Reasons Why Wheel Bearings Fail
Understanding the causes can help you prevent premature failure. It’s rarely just one thing; usually, it’s a combination of factors.
- Impact Damage: Hitting a deep pothole, curb, or road debris can shock the bearing, denting the races or balls.
- Faulty Installation: If a bearing wasn’t pressed in correctly or was damaged during installation, it won’t last long. Over-tightening is a common installer mistake.
- Worn Seals & Contamination: The bearing seal keeps grease in and dirt/water out. A torn seal lets contaminants in, which acts like sandpaper inside the bearing, grinding it down.
- Lack of Lubrication: Over time, grease can break down or leak out. Without proper lubrication, the metal-on-metal contact creates extreme heat and rapid wear.
- Driving Conditions: Frequent driving on rough roads, through deep water, or in very dusty environments accelerates wear.
- Vehicle Modifications: Installing heavier wheels and tires than the vehicle is designed for puts extra stress on the bearings.
How to Tell Which Wheel Bearing Is Bad: The Top Symptoms
Listen and feel for these warning signs. Catching a bad bearing early is cheaper and safer.
1. The Growling or Grumbling Noise
This is the most classic symptom. It sounds like a constant, low-pitched rumble or growl that increases with vehicle speed. The noise often gets louder in turns, as weight shifts.
2. A Humming or Roaring Sound
Similar to the growl, a humming noise that changes pitch with speed is a strong indicator. It might be mistaken for tire roar, but it won’t change on different road surfaces like tire noise often does.
3. Clicking or Snapping Sounds
In early stages, or with certain bearing types, you might hear a repetitive clicking sound, especially at lower speeds. This can indicate a damaged roller or cage.
4. Wheel Vibration or Wobble
As the bearing loosens, it allows the wheel to have slight play. This can cause a steering wheel vibration that gets worse at higher speeds, similar to an unbalanced tire.
5. Uneven Tire Wear
A severely loose bearing can cause the wheel to tilt, leading to unusual and uneven wear on your tire tread. This is often a later-stage symptom.
6. ABS Malfunction Lights
Modern wheel bearings often have a built-in sensor ring for the ABS system. If the bearing fails, it can damage this ring, causing your ABS or stability control warning light to illuminate.
Pinpointing the Exact Bad Wheel Bearing: A Simple Test
You’ve heard a noise, but how do you know which wheel it’s coming from? Here’s a safe, step-by-step method you can try.
- Find a Safe Location: Park on level, solid ground like a driveway. Engage the parking brake and put blocks behind the wheels.
- Lift the Vehicle: Safely jack up one corner of the car so the wheel is completely off the ground. Always use a jack stand for support—never rely on the jack alone.
- The Grab Test: Place your hands at the 12 and 6 o’clock positions on the tire. Try to rock the wheel in and out. Any noticeable clunking or movement suggests excessive bearing play.
- The Spin Test: Spin the lifted wheel by hand. Listen and feel for any grinding, roughness, or catching. A good bearing spins freely and quietly. Compare it to other wheels on the car.
- Test While Driving: This requires a helper. Drive in an empty parking lot. Making a gentle turn to the left will shift weight to the right side, often making a right-side bearing noise louder. Turning right makes a left-side bearing noise more pronounced.
If your not comfortable doing this, a mechanic can diagnose it quickly. Its a common check for them.
Your Next Steps After Diagnosis
You’ve identified a failing wheel bearing. Ignoring it is not an option, as it can seize or collapse, leading to a wheel coming off. Here’s what to do.
Immediate Actions
- Reduce Speed & Avoid Stress: Drive slower and avoid rough roads, potholes, and hard cornering until it’s fixed. Limit long trips.
- Schedule Repair Promptly: This is not a repair to postpone. Contact a trusted mechanic or, if you’re experienced, prepare to do it yourself.
Repair Options
Wheel bearings are typically sold as a complete hub assembly for modern cars, which makes replacement more straightforward.
- Parts Purchase: Buy a quality replacement hub assembly or bearing kit for your specific vehicle. Don’t skimp on quality here.
- Professional Repair: For most people, this is the best choice. A mechanic has the press, tools, and torque specs to ensure a safe, correct installation. They will also check related parts like the axle nut and CV joint.
- DIY Replacement: This is an advanced job requiring special tools like a large socket set, torque wrench, and often a hydraulic press. If you have the skills and tools, follow a vehicle-specific repair guide closely.
After replacement, the mechanic should test drive the vehicle to confirm the noise is gone and ensure everything is secure.
FAQs About Bad Wheel Bearings
How long can I drive on a noisy wheel bearing?
It’s a risk. You might drive for weeks, or it could fail catastrophically on your next trip. It’s impossible to predict, so get it checked immediately.
Can a bad wheel bearing cause shaking?
Yes, a worn bearing can cause steering wheel vibration, especially at higher speeds. This shake often gets progressively worse.
Is a wheel bearing repair expensive?
Cost varies by vehicle. Parts for a common sedan can range from $80-$250 per wheel, plus 1-2 hours of labor. Four-wheel-drive and luxury vehicles are often more expensive due to part cost and complexity.
What’s the difference between wheel bearing noise and tire noise?
Tire noise often changes with road surface (asphalt vs. concrete) and may have a rhythmic pattern linked to tread wear. Bearing noise is a constant growl that changes primarily with speed and steering load.
Do wheel bearings fail suddenly?
They usually give plenty of audible warning. However, if a bearing is damaged by a severe impact, it can fail much more quickly without the typical long growling period.
Should I replace wheel bearings in pairs?
It’s often recommended, especially if the vehicle has high mileage. If one has failed due to age and wear, the opposite side is likely not far behind. Replacing both sides ensures balanced performance and can save on future labor costs.
Final Thoughts on Wheel Bearing Safety
Your wheel bearings are a silent workhorse until they’re not. Recognizing the early signs—that persistent growl, a new vibration—is key to preventing a dangerous situation. The diagnostic tests are simple, and the repair, while technical, is a standard procedure for any shop. Don’t ignore the warning sounds your car gives you. Addressing a bad wheel bearing quickly protects your safety, your tires, and your wallet from more extensive damage down the road.