Wheel bearings are one of those mysterious aspects of automobiles that many people fail to understand. Unfortunately, a bad wheel bearing can lead to serious problems--problems that can put you at unnecessary risk, and cost a bundle to fix. Thus it pays to know at least the basics about wheel bearings. If you would like to improve your knowledge of automotive problems, read on. This article will provide answers to three common questions about bad wheel bearings.

What are the symptoms of a bad bearing?

The most common manifestation of a bad wheel bearing generally involves an unusual sound. This sound is often described as a whirring or roaring noise--one that seems to grow more pronounced as the vehicle accelerates. That said, the sound often diminishes or even disappears once a car reaches highway speeds. Expect such sounds to grow more and more noticeable as the bearing continues to wear down.

How can I verify whether my whirring sound is caused by a bad wheel bearing?

As with many symptoms of automotive trouble, that strange roaring sound coming from underneath your car may in fact be caused by something other than a bad wheel bearing. Poor alignment, worn tires, and problems with the CV joint can all lead to similar sounds. In order to determine whether a bad bearing is indeed the cause, you will need to have the problem evaluated by a reliable mechanic.

They will perform a series of tests to pinpoint the cause of the unusual sound. For one thing, they will attach special stethoscopes to the underside of the car. These allow them to listen to the wheel bearings "up close," while taking the car on a test drive. Likewise, they will put your car on a lift to test the bearing from play. A loose or wobbly wheel is a strong indication that you're dealing with bad bearings.

What causes bearings to go bad?

The primary cause of bad wheel bearings is a combination of simple wear and tear and exposure to the elements. You see, although the bearings are packed in waterproof grease and sealed in place, these seals are not completely water tight. That's because they have to be just loose enough to allow pressure generated by the bearing lubricants to escape.

Over time, as small amounts of moisture make their way into the bearing housing, the lubricating grease becomes emulsified. Likewise, contaminants cause the grease to become increasingly thick and sludgy. Both of these things lead to an increase in the amount of friction the bearings are exposed to. Eventually this friction will cause the bearings to break down--thus resulting in those unsavory noises you've been hearing.

To learn more, talk to a service like G P Automotive.