Do you hear a loud growling or rattling noise every time you take a sharp turn? Has someone told you that it might be a wheel bearing problem but you don’t know the first thing about it? If that’s the case, you better learn about it, and quickly.
Driving with a faulty wheel bearing is extremely dangerous and you could end up wrecking your car and hurting yourself. Let’s get into all the reasons your car is making that awful noise and what you can do to fix it.
What Is a Wheel Bearing?
A wheel bearing is essentially a set of two steel rings that are encased in a metal ball. The rings help your wheels spin as fast as possible, without causing any friction. Pretty much every type of vehicle, from bike to airplane, has wheel bearings.
In your car, the wheel bearings sit on the metal axle shaft, which is tightly fitted around the hub. They’re an essential part of every car, and when they’re working right, they help with fuel economy, performance, and they reduce tire wear.
Types of Wheel Bearings
There are a couple of types of wheel bearings you’ll see in most vehicles:
- Ball bearings
- Tapered roller bearings
- Precision ball bearings
- Roller bearings
You’ll find ball bearings in commercial vehicles and they can be used on wheels of different sizes. They can also absorb both thrust and radial loads and work great for cornering.
Tapered roller bearings are shaped like a cone so that they can handle bigger thrust loads and you’ll find them in most trucks or bigger cars. On the other hand, precision ball bearings were designed to perform well at high speeds and sharp turns. That’s why they’re installed in planes and racing cars.
Roller bearings aren’t really that widespread because they can’t handle turns well. But due to their ability to take a lot of weight, they’re the perfect choice for dollies and grocery carts.
Driving With Faulty Wheel Bearings
Let’s get this right out of the way — you can drive with a faulty wheel bearing, but you probably shouldn’t.
For starters, it will destabilize your car and put pressure on your tire. Even if you’re an experienced driver, by going on the road with a bad wheel bearing, you’re jeopardizing your life and the lives of those around you.
Now I know you’re probably thinking, So what if I have a bad wheel bearing? What’s the worst that could happen?
Well, if just one of your wheel bearings seizes up while you’re driving, it’ll lock your wheel as if you slammed the breaks on it. When that happens, your car will start spinning uncontrollably and you could get seriously injured.
If you have to drive anywhere, like to a mechanic, for example, be extremely careful. Turn on your hazard lights and go slowly. That way, even if your bearing seizes up and locks your wheel, you’ll be able to control your car much better at a lower speed.
Why Do Wheel Bearings Make Noise?
So now that you know how dangerous a faulty wheel bearing is, the question remains, what causes it? Most often, there are four culprits to blame for the excessive noise.
Your entire car wheel system consists of the wheel bearing, tires, shocks, lower and knuckle arm, as well as the lower joint. When your tires aren’t balanced, there’s more pressure on the whole system and it gets damaged more easily.
In turn, any of these parts could start making a loud noise that’ll drive you insane while you’re driving. Also, the same thing will happen if your shocks aren’t set properly.
There’s a chance that your wheel bearings will start clunking and squealing even if they’re new. If that’s the case, it means that your mechanic didn’t install them properly and they’re already damaged.
Driving on Rough Terrain
Sometimes, you can’t avoid driving on a rough road or over a big pothole. But since your wheel bearings take all the pressure from your car’s weight, they can easily get damaged on impact.
First, they usually begin to crack a little bit, not enough for you to even notice. But over time, if you continue driving on rough terrain or hitting all sorts of bumps, the problem will become much worse. Not only that, but the noise coming from the broken wheel bearing will become deafening as well.
Going Through Water
Wheel bearings are greased with petroleum jelly that keeps them running smoothly. However, when you drive on wet roads or go through water, water droplets can get on the bearings. Once the water mixes with the jelly, the bearings become almost useless.
They can’t handle the friction and the weight, so the balls will start rubbing against each other. The grinding coupled with the damage that’s already happening on your bearings will make a lot of noise.
What Kind of Noise Do Wheel Bearings Make?
If you’ve damaged your wheel bearings, your car will tell you what’s going on by letting out a noise. Most often, there are three specific sounds you could hear:
Growling & Squealing
There’s a pretty big chance that, if your wheel bearing is busted, you’ll hear a loud, growling or squealing sound coming from your tires. Usually, it happens when you’re driving at high speeds or quickly accelerating.
The trouble with growling is that it can disappear at any moment, so you have to pay attention to it. On the other hand, it could get a lot louder with every turn you make.
You might also hear cyclic chirping or squealing, instead of the growl. So if you suspect there’s something wrong with your bearings, keep your ear to the ground.
Humming can be a lot more difficult to detect, especially if you haven’t soundproofed your car. But if you have and you still hear a loud humming noise, it’s probably your wheel bearings.
A dead giveaway that you need to fix your wheel bearing is if you hear a howling noise when you slow down. When it’s overworn, the bearing won’t support the gears properly, thus creating the noise.
However, if you hear howling when you’re speeding up, it’s not the bearing, it’s your gears. Either way, this sound only means trouble, so you should go to a mechanic as soon as possible.
Other Signs That the Wheel Bearing Is Faulty
In addition to the humming, howling, and growling, there are other telltale signs there’s something wrong with your bearings, like uneven tire wear.
Uneven Tire Wear
For example, if they’re working fine, all of your tires will look pretty much the same. But if one of your bearings is faulty, the tire tread will disappear much faster and you’ll have to replace that tire sooner than the others.
Vibrating Steering Wheel
Another sign that you need new bearings is if your steering wheel is vibrating while you’re driving. You’ll probably notice the problem even when driving at lower speeds, but it’ll get much worse when you accelerate.
The Car Slightly Pulling to One Side
When the bearings corrode and pit, the lining that protects the wheels from surface vibrations starts disappearing. Since all the pressure’s on the bearings, they quickly wear out, and are thus unable to do their job.
Then, the destabilization kicks in and your car starts pulling to one side (where the bearing is weak). You’ll especially feel the pulling when you step on the brakes.
Wobbling wheels might be tricky to detect, especially if you can’t lift up your tires off the ground using a jack stand or hydraulic lift.
How to Diagnose Faulty Wheel Bearings
While you could just follow the noise and take your car straight to the mechanic, there are also some tests you can run to confirm your suspicions.
Lift Your Tires Off the Ground
To determine if your wheels do wobble, you’ll have to get a jack stand or hydraulic lift to get the tires off the ground. Take a wheel and put your hands at the 12 and 6 o’clock position. Then, rock the wheel slowly back and forth while keeping an eye out for any movement.
You should also grab the tire at the 3 and 9 o’clock position and repeat the motion. Keep in mind that there should be no movement or wobbling while you’re doing this or after you’ve let go.
You should repeat these tests with every wheel so that you can pinpoint exactly which wheel bearing is causing the problem. If there’s any movement, that wheel bearing has to go.
Do a Speed Test
Another way to try and figure out if the wheel bearing is faulty is by doing a simple speed test. You’ll have to maneuver your car left and right while changing speeds and accelerating. Of course, try to find an empty road somewhere so that you can perform this test safely.
While you’re driving on a flat road and speeding up and slowing down, you should slightly turn the wheel from the 10 to 2 o’clock position. Doing anything more than that is not only overkill, but it’s also dangerous.
When you’re doing this, you could see one of two things happen. Either your steering wheel will begin vibrating or the bearings will start howling.
Use an Electronic Stethoscope
If you know that it’s the wheel bearing that’s causing all the commotion, but can’t pinpoint which one, you should get an electronic stethoscope. This nifty little tool will help you figure out which of your bearings needs to be replaced.
With an electronic stethoscope, you’ll have a set of microphones that you hook up to your wheels. Then, start your car and take it for a drive while somebody else listens to the noise that’s coming from each transmitter.
I found that the two best electronic stethoscopes for the job are the Steelman Rattle and Squeak Finder and the Allosun tester. If you’re looking for something cheap that you can easily resell later, go with the Allosun.
But if you want a precise stethoscope that’ll last you a lifetime, I recommend the Steelman. It comes with a 16 ft cable and has six microphones.
How to Repair Faulty Wheel Bearings
Now that you’ve diagnosed the problem, it’s time to start thinking about how you’re going to fix it. You have two options: do it yourself or take your car to a mechanic.
If you go for the DIY option, you’ll need a lot of tools and some serious knowledge of how the wheel system works. First, you should start by looking at your car’s manual and checking out this instructional YouTube video.
If the bearing isn’t broken, you could get away with putting some more grease on it and tightening the screws. But if it’s more serious than that, I recommend you go to a professional.
The Cost of Replacing Wheel Bearings
Front Wheel Bearings
If you’re replacing only one wheel bearing on the front side of your car at a mechanic shop, you can expect to pay anywhere around $130 to $220.
But replacing both front wheel bearings is a pretty labor-intensive job, so you’ll have to pay more. With that said, the parts alone will set you back $120–$200, while your mechanic could charge you up to $280 for the work.
The overall price will depend on the make and model of your vehicle. But if you have a bigger car, truck, or an SUV, expect to pay more.
Rear Wheel Bearings
Rear wheel bearings are a bit cheaper than the front ones. If you’re just replacing one bearing in the back, the price will be around $120 to $240 for both the parts and the labor.
If you have to replace both of the bearings in the back, it’ll cost you anywhere from $240 to $460. On the bright side, when properly installed and maintained, wheel bearings can last you a long time. So even though these prices may seem a little steep, you won’t have to pay them every couple of months.
If you hear your car growling or squealing while you’re driving down the highway, it’s time to have your bearings checked. They might just need to be greased up a bit or you might have to replace them. Either way, make sure you get on that as soon as possible. Otherwise, you’re putting your life at risk every time you get behind the steering wheel.