After you use a bearing, it starts to cool off and then a vacuum is generated from the lubricant, air, and contacting metal. The seals should hold the vacuum in place. If not, the sealed hub or the bearing will start pulling in air from the outside, which may include water and other debris. If you are in a certain location in the U.S. which has salty roads, it would be like smothering your wheel bearings with ocean water, resulting in the wheel bearing being damaged or have noise coming from it.
What causes noise from the wheel bearings?
Wheel bearings are attached to the wheel and are constantly moving. Since the wheels are touching the road while driving, there could be a variety of reasons why the wheel bearing is making these strange noises or enduring damage. The main reasons are below.
1. Poorly Installed
If your wheel bearings got replaced not too long ago, then it would be very strange if they were failing any time after that. The only conclusion is that the wheel bearings endured damage because they were installed improperly or against the manufacturer’s recommendation.
2. Driving On The Street Floods
The manufacturer of a car lubricates the wheel bearings. If they used a lubricant that is based from petroleum, it will cause pressure on the wheel bearings if they become disturbed. Wheel bearing seals are designed by engineers in a way so the pressure can leave the wheel bearings. The only bad thing is that these seals cannot stop water from getting through. This means if you were to drive your car on a street that is flooded with water, then your bearings would be subjected to moisture. Once that happens, it mixes with the lubricant and makes it ineffective, causing the bearings to endure damage. You would not be able to service or repair a modern style wheel bearing either. The only solution from water damage is to replace the wheel bearing completely.
3. Driving On The Rough Roads
The wheel bearing will receive all the pressure of the tire and wheel. If you were to drive over a bumpy curb or pothole, the wheel bearing could be subjected to damage very easily. When you hit something, the bearing’s balls will likely get forced into the race. The result will be small imperfections in the bearings. As you continue to drive the car with these imperfect bearings, it will cause more wear and heat to form. Soon the wear will cause debris to form and this will pollute the lubricant of the wheel bearing and make it fail a lot faster. However, it is possible the failure could take a few months before it is noticeable.
4. Unbalanced Tires and Bad Shock
The wheel system depends on its wheel bearing, tire, lower arm, lower joint, knuckle arm, and shock. When there are unbalanced tires on a car that you’re driving, some of those other parts could be damaged and then it will make noise come from the wheel bearing.
5. Accident On The Wheel Area
Wheel bearings are constantly in motion and they are connected to all the other parts mentioned in the last section. So, if the wheel area were to be subjected to an accident, then the wheel bearing would be 100% damaged and then cause noise to form.
How to Diagnose Damaged or Noise Wheel Bearings
Take a jack and use it to lift the vehicle up until the tire is not on the ground. Now try moving the tire in a vertical direction, and then a horizontal one. If the wheel feels free play, then there might be damage to the bearing.
A video has been made to demonstrate how to perform this inspection of the wheel bearing. Just remember the noise you hear from the wheel bearing tends to vary. The noise you hear depends on how badly the wheel bearing is damaged.
Speed may also contribute to the noise from the wheel bearing. Sometimes you may go 100 km/h and hear the noise, but then go 110km/h and not hear the noise anymore. This may happen only if there is a small amount of damage to the bearing. Therefore, you may not be able to notice this right away. You will only be able to tell by feeling the tire free play like mentioned above. At this point, take your car to the auto body shop and have it looked at by a professional. They can figure out if there is damage to the wheel bearing or if another part is damaged like the wheel rim or the tire.