What are Wheel Bearings?

In general, Wheel bearings are components that feature small metal balls placed within races. Across the industry, there are two common types of wheel bearings which are ball and roller bearings. Roller bearings consist of small cylinders that are situated within a tapered circular housing, often being unsealed. While this can promote easier maintenance procedures, a lack of sealing can lead to increased contamination. Ball bearings, on the other hand, are those that feature balls with small contact points, ensuring ease of rolling. With proper sealing, a ball bearing can prevent contamination at the expense of lacking serviceability. With the implementation of wheel bearings within an automobile, wheels are capable of spinning freely while rolling friction is reduced. Wheel bearings are placed within the wheel hub of the assembly, that of which is the part that attaches each wheel to the axle.

In proper conditions, a wheel bearing can last upwards of 75,000 to 100,000 miles while undertaking driving loads, though this length can vary based on the manufacturer of the bearing and operating conditions. There are a few ways in which one can determine whether or not their bearings are beginning to reach the end of their lives, and operators should familiarize themselves with the most common symptoms. The most widely faced symptom is the instance of weird noises coming from bearings during operations, these including humming, rumbling, clicking, grinding, or other various sounds.
 
As Bearings begin to wear down over time, they may also start to loosen and performance will decrease. This can lead to an uneven breakdown of tires which can be used as evidence for a faulty bearing. Steering may also begin to feel loose as bearings wear down, typically resulting from wheel assembly issues. Wheel lock is also a major issue, stemming from the buildup of dirt, contaminants, and other substances that cause friction to increase with the loss of lubrication. If the issue stems from the contamination of wheel bearings, vibration may occur. Alongside such issues, other common signs of a failing wheel bearing include traction control or ABS malfunctioning, those of which will often cause a warning light to appear within the vehicle.
 
When any Roller bearing or ball bearing begins to break down, it is best to replace the component so that performance and health may be maintained. It can be useful to replace all bearings at the same time so that tracking general service lives is much easier. Additionally, standard procedures and proper wheel hub assembly removal should be adhered to during replacement operations for the safety of individuals.