Wheel bearings

The wheel bearings are situated inside the wheel hub. The wheel bearings allow the wheels to turn with little friction. The hub usually has two bearings an inner and an outer one. Another crucial part of the wheel assembly is the seals to protect the bearings from dirt and any other foreign matter that may damage the bearings. The bearings are covered with lithium grease for lubricating purposes and because it can handle the heat created by the bearings and the brakes. If there is no grease/little on the bearings it will cause the bearings to create a lot of heat as the wheel turns, the bearings will expand because of this and seize. Once the bearings cool down they may be able to turn again but the will be damaged and will need to be replaced. A damaged wheel bearing can affect the vehicles handling/operation and the passengers' safety.

We pulled a wheel hub apart and cleaned it with brake cleaner. We found that the inner bearing's outer race had marks on it. In this case the hub would be fitted with a new bearing kit (inner bearing, outer bearing, lithium grease and new seals). If one bearing is damaged it is best to get a bearing kit as the other bearing may wear out soon after. When re-assembling the wheel hub it is important that the adjustment nut is not over tightened as this will put a lot of force on the bearings and it can cause them to wear out faster or even cause it to seize. It is also important to make sure that the grease cap and the grease retainer seal properly.