Wheel Bearing Warning Signs

Without good, strong wheels, your car cannot operate safely or properly. What you may not know is that the wheel is far from a simple component. In fact, the design of a wheel is very complex and several components must be integrated together.

A good example of this is the wheel bearing. Wheel bearings are essential for your wheels to work together - especially for the coordination of hubs, tires and components. They are also susceptible to abuse, which is why it's important to know the warning signs. But before we dive into bad bearings, symptoms, effects and costs, it's equally important to know what it is.

What is a wheel bearing?

A wheel bearing is a set of steel balls held in a metal ring called a seat ring. In the center of the wheel is a hollow piece of metal called the hub. Wheel bearings are fitted tightly inside this hub and mounted on a metal axle to help reduce friction as the wheel rotates.

They are different from engine bearings because wheel bearings do not have a constant source of lubrication, which means they need to be tight enough to keep out water and road dust. They also support the entire weight of the vehicle while driving, which is why they are subject to lateral forces on rough roads, potholes, and during cornering.

Like most car parts, wheel bearings will eventually wear out and may even need to be replaced. How do you know when you need to replace your wheel bearings or at least have your vehicle inspected by an automotive professional? Watch for some key warning signs of a broken wheel bearing.

How to tell when a wheel bearing is bad

Ball bearings are the most common type of wheel bearing today (along with roller bearings - although the latter do not have the versatility of ball bearings). Other types include tapered roller bearings, which are primarily used in trucks, and precision ball bearings, which are designed for intense radial loads. Regardless of the type of vehicle you have, the warning signs are the same, especially for bad sounding wheel bearings.

Here are a few things to remember.

▴ First, listen! The most common and easily identifiable symptom of a damaged wheel bearing is the sound. If you notice a grinding or scraping sound coming from your wheels or tires, be aware that this is likely due to a damaged wheel bearing - especially if the noise becomes louder when the vehicle accelerates.

▴ One telltale sign of a damaged wheel bearing: a car that feels loose while driving. Loose can be difficult to express, but basically, it means that your car seems less responsive or less precise than usual when you notice it steering. Loose steering isn't always due to a wheel bearing problem, but it usually can be. Sometimes wheel bearings can wear out, causing them to come loose inside your wheel assembly.

▴ Another related phenomenon is pulling. When you drive, does the car follow your instructions, or does it seem to have a mind of its own and steer in a particular direction? Again, this isn't always due to a faulty wheel bearing, but it is certainly the culprit.

▴ Finally, pay attention to your tires. Changing your tires regularly will help prevent wear - but if you notice extremely uneven wear, you may need to check your wheel bearings.

How to tell the difference between bad wheel bearing noise

1. Humming sounds

There are many sounds that vehicles make that are of concern, so it's important to distinguish them to avoid misdiagnosis. Noises can be misleading: a buzzing noise while driving can be caused by a number of different problems, starting with your tires, but it could also be wheel bearings or CV joints.

2. Squealing and growling

The typical sound of a bad wheel bearing is a periodic chirp, squeal and/or growl. If the sound varies in proportion to the speed of the car, you can also tell that the sound is related to the wheel bearing. The sound will get worse with each revolution, or it may go away temporarily.

3. Rear differential noise and wheel bearing noise

A whine that occurs only during deceleration is a good indicator of a loose pinion bearing preload. If the whine occurs under acceleration at different speeds, the gears may be worn. However, excessively worn bearings can also produce whine when they do not properly support the gears. They also tend to rumble during cornering.

Bad wheel bearings are a serious problem

In short: a problem with wheel bearings can affect the smoothness of your ride and the life of your tires, but more importantly, it can lead to real safety issues. That's why it's important to check your wheel bearings at the first sign of a problem.

Don't take this often overlooked component of your car for granted. Pay attention to these warning signs. At the first sign of a problem, pull the vehicle in and have a professional check the wheel bearings.