Wheel bearings are a crucial part of wheel assembly in vehicles. Basically, wheel bearings allow the wheel of vehicles to rotate smoothly with minimum friction. When in great shape, the wheel bearings hold the wheels in place and produce no noise while driving. However, when a wheel bearing goes bad, it is a completely different story.
Bad wheel bearings will sometimes turn on ABS, traction control, and check engine lamps because the ABS tone wheel is built into the bearing. The system doesn’t read the wheel speed correctly and will turn on the dash lamps.
The worst thing you can do if you have a bad wheel bearing that’s making noise is to drive it long distances at high speeds. That’s where you can really get into trouble. Once the airflow over the vehicle becomes greater, it’s harder to hear the noise. Just because you can drive faster and the wheel bearing doesn’t sound as loud, that doesn’t mean it’s okay.
A noisy wheel bearing is trying to tell you something. I would recommend if you do hear a noise from your bearing, just drive it home or drive it to a repair shop.
In this article, I am going to talk about bad wheel bearing noise, symptoms, and diagnosis.
To diagnose a bad wheel bearing noise, you must first determine where the noise is coming from (front, back, left, or right side). Jack the side that the noise is coming from and test the tires for play by holding them in a 3 and 9 and 6 and 12 hand position.
What Is Wheel Bearing In Cars
Wheel bearings are sets of steel balls held in place by a metal ring and are an essential part of the wheel assembly that is used to connect the wheel and the axle. The wheel bearings support the weight of the whole vehicle and this is why they go bad much faster if you drive on roads with potholes and rough roads.
Ball bearings are one of the most common types of bearing used in most passenger vehicles. A ball bearing consists of a row of balls as rolling elements. They are trapped between two annulus-shaped metal pieces. These metal pieces are known as races. The inner race is free to rotate while the outer race is a stationary ball.
Bearings provide very low friction during rolling but have limited load-carrying capacity. This is because of the small area of contact between the balls and the races. They can support axial loads in two directions besides radial loads.
Depending on the application, different types of ball bearings are available such as deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings, and thrust ball bearings. It also helps if you spin the tire and listen for a grinding noise.
Deep groove ball bearings
The deep groove ball bearing is the most widely used ball bearing. Trapped between the two races is a ring of balls that transmit the load and allows rotational motion between the two races. The balls are held in place by a retainer. They have very low rolling friction and are optimized for low noise and low vibration.
Angular contact ball bearings
In the angular contact ball bearing, the inner and outer races are displaced with respect to each other along the bearing axis. This type of ball bearing is designed to handle greater amounts of axial loads in both directions in addition to radial loads.
Self-aligning ball bearings
Self-aligning ball bearings have deep grooves on the inner ring, similar to deep groove ball bearings followed by two rows of balls and an outer ring. The outer ring has a concave shape and this grants the inner ring.
Thrust ball bearings
Thrust ball bearings consist of two bearing discs with raceways for the balls. These bearings exhibit low noise, and smooth operation, and are capable of high-speed applications.
What Noise Does a Wheel Bearing Make When It’s Going Bad?
When a wheel bearing starts to go bad it makes a grinding, growling, and whining type of noise. It is described as a sound same as when you stick a playing card in the spokes of a spinning bicycle wheel. A bad wheel bearing doesn’t go bad instantly. In fact, there are three stages a wheel bearing goes through before it completely fails.
A bad wheel bearing is most audible between 20 and 50 mph.
This is what a bad wheel bearing sounds like:
The first stage of a bad wheel bearing is the noise. You will notice that your vehicle just sounds very differently while driving. If you roll down your windows and turn off the radio, as soon as you start driving, you will hear a grinding, growling, and whining noise. The noise increases with the speed.
As you disregard the noise and continue to drive your vehicle, the wheel bearing will only go even worse. Apart from the increased noise, the wheel bearing will start to get loose. The wheel bearing is what connects the actual wheel to the axle. A properly working wheel bearing will hold the tire in place and will allow it only to roll forward or backward. On the other hand, a bad wheel bearing isn’t holding the wheel in place as it should and often the wheel starts to wiggle in a camber (archy) direction.
If you disregard the second stage of a failing wheel bearing, stage three is a catastrophic failure. A completely failed wheel bearing can lock the tire and don’t allow it to move anymore. This is where the wheel can separate from the axle and you can lose a wheel while driving. I really don’t need to explain how dangerous it is to drive without one tire.
How To Diagnose a Bad Wheel Bearing
Noise from a bad wheel bearing can be sometimes misleading. You are driving down the road and you just hear this growling and grinding noise coming from all sides. Following these steps will help you diagnose a bad wheel bearing and avoid changing the wrong part.
1. Split the noise left to right, front to rear
Determining where the noise from a bad wheel bearing is coming from can be confusing. This is especially true if you are diagnosing a bad wheel bearing for the first time. However, as the saying goes ”divide and conquer”, this is what you should do. Try getting someone with you in the car as you test-drive it. Make the person sit in the back.
While you drive, you will be able to determine if the noise is coming from the front of the vehicle, while the person in the back will be able to hear if the noise is coming from the rear. As a driver, you can really go left or right. But the person that is with you can switch positions and pinpoint the sound.
If you are unable to pinpoint the sound to the actual wheel, don’t worry. At least make sure that you are able to determine whether the sound is coming from the front or the back. This will save you from the trouble of jacking your vehicle twice.
2. Jack up the car
Like I said before, determining whether the noise is coming from the front or the rear will save you the trouble of jacking your vehicle twice. So, if you have determined that the noise from the bad wheel bearing is coming from the front, jack the front of the vehicle.
Once the vehicle is jacked, support it on jack stands and block the other wheels so the car won’t roll. At some point in diagnosing a bad wheel bearing, your hand will be underneath the tire. This is why it is very important that you are certain that your vehicle is stable.
3. Check for play in the wheels
With the vehicle jacked, position yourself in front of the tire and place your hands on the left and right sides of the tire (3 o’clock and 9 o’clock positions). Shake the tire back and forth and look for any movement or play.
Sometimes you can also hear a clicking noise while you do that. If there is some play in this tire, place your hands on top and the bottom of the tire (12 o’clock and 6 o’clock positions). Shake the tire back and forth. If there is still play, this wheel definitely has a bad wheel bearing.
4. Spin the tire
Keep in mind that not all bad wheel bearings will have a play. Or, they might have a play but it won’t be very noticeable. Some of the wheel bearings that go bad actually just aren’t moving as freely as they should and are feeling gritty when spinning.
So, spin the tire as fast as you can and try to hear if there is any grinding noise coming from it. Standing in front of a spinning wheel with a bad wheel bearing will allow you to hear that growling, grinding, or metallic humming sounds.
5. Check if the tire rod is bad too
Sometimes a bad tire rod can cause noise and play in the tire. We want to make sure that it is the wheel bearing that has gone bad and not something else. This step should be done especially if you have play in the wheel in one direction (left to right, or up to down).
Again, place your hands on the tire on the left and right sides and shake the wheel back and forth. This time, you will be looking behind the tire. If you are unable to shake the wheel and look behind the tire at the same time, place a camera and record the movement of the tire rod, the lower ball joint, and the upper ball joint. As you shake the wheel, the tire rod, lower back joint, and upper ball joint shouldn’t move.
Next, place your hands on the top and the bottom of the tire and shake it back and forth. Again, the tire rod, the upper and lower ball joints shouldn’t move. If they move, you might not have a bad wheel bearing, or you have a bad wheel bearing, plus some other parts of the wheel assembly.
6. Scan the vehicle for codes
Just to be absolutely sure that you have a bad wheel bearing, you can scan your vehicle with an OBD scanner. However, this will work on newer vehicles that use an ABS sensor in the wheel hub bearing. If it detects a problem with the ABS sensor and it is going to throw a code on the dashboard. I would definitely do this if I see an ABS light on my dashboard or a traction control light.
Locate the OBD port underneath the steering wheel and connect your scanning tool. The scanning tool is going to read all the faulty codes and will give you an exact report of what’s wrong with your vehicle. There isn’t a specific trouble code for a bad wheel bearing. However, the trouble code will be associated with the ABS and if you scroll into the frequently reported fix tab, you will see that it says to replace the wheel bearing assembly.
How Long Can I Drive With a Bad Wheel Bearing?
If your wheel bearing has only just begun to go bad and you are only starting to hear a whining noise, you can probably drive about 500 miles before it goes to the next stage in which the wheel bearing starts to get loose before it completely detaches itself from the axle.