Why does my wheel hub bearing run dry? Is lubrication the only cause of hub bearing failure? Matthias.
Hello Matthias, a wheel hub bearing is a set of ball or roller bearings housed in a rotary casing. These bearings are coated with a fine layer of grease, which serves to lubricate, cool, and protect them from frictional wear. The primary function of hub bearings is to allow the vehicle’s wheels to rotate smoothly while minimising friction between the wheel hub and the axle. When hub bearings begin to fail, you may notice symptoms such as wheel wobble, the car pulling to one side, poor drivability, steering vibrations, or unusual humming and clicking noises. Wheel hub bearings can fail due to several reasons. One common cause is ageing or wear and tear. Over time, the bearing seals degrade and start to leak the long-life grease, resulting in lubrication failure, increased friction, overheating, and ultimately, bearing seizure or complete failure.
Corrosion is another cause of hub bearing failure. When the casing corrodes, it can damage the seals and internal bearings of the hub unit, accelerating their deterioration. Similarly, contamination of the grease by dirt or debris leads to gradual but certain bearing failure. Overloading a vehicle also puts undue stress on the hub bearings. Carrying loads beyond the vehicle’s recommended capacity can lead to overheating and excessive wear. In addition, road impacts, such as hitting potholes or rumble strips at high speeds, can damage the hub bearings. Impact during a collision can also cause immediate and severe bearing failure. To ensure longevity and performance, proper fitting and regular inspection of hub bearings are essential.
