Wheel bearing for your car

High performance at a critical hub: the wheel bearing

The wheel bearing is the ultimate connection point between wheel and drive. It makes sure that the wheel revolves as free as possible. A defective wheel bearing causes a specific noise which gradually becomes louder. Its replacement is not really simple, although it can be done in the home garage provided you have the proper tools. The repair of this part requires a considerable amount of strength.

Construction of a wheel bearing

A wheel bearing serves to keep the wheel's rolling resistance as low as possible. Rolling resistance generates friction and heat, resulting in quicker wear and higher fuel consumption. Wheel bearings are therefore generally large ball bearings, placed in two rows. A wheel bearing has permanent lubrication. On the non-driven wheels the grease is held in place by a lid. On the driven wheels, generally the front wheels, the wheel bearing grease is contained in a rubber sleeve.

Location of the wheel bearing

Several locations are possible for the wheel bearing. On the driven front axle, the wheel bearing sits behind the axle sleeve in the wheel. On the rear axle the wheel bearing is often installed in the drum brake. In all cases, the wheel hub must be disassembled to get access to the wheel bearing.

Replacing a wheel bearing

The wheel support is fixed on the axle with a large tight screw, requiring a pneumatic screwdriver with a long lever to unscrew it. When the screw and snap ring (if present) are loose, the hub can be removed. This was the easy part. The greatest challenge is removing the wheel bearing from the hub and pressing the new bearing in. A special tool is required: the hydro-mechanical press.

No replacement without press

Knocking the wheel bearing from the hub with a hammer and a chisel is a very bad idea, damage being the main result. Pressing in a new bearing is not possible without the press. Removing and installing bearings can be done by a professional garage at a relatively low price. However, the garage does not provide a guarantee for the work and certainly for the bearing if the parts were not purchased there. Be careful of the assembly direction when pressing in new bearings. Furthermore it is important to apply the right torque when assembling the wheels. Too much can cause as much damage as too little.

What causes wheel bearing malfunction?

A wheel bearing is under permanent strain, revolving millions of times under varying stress circumstances and carrying several tons in weight. This is why a wheel bearing is a wear part. Rough driving hastens the ageing process more than a relaxed driving style. Apart from the natural ageing, a defective axle sleeve is a common cause of a wheel bearing wear. When the grease leaks out, the wheel bearing is no longer adequately lubricated. Furthermore, penetrating salty water or dirt additionally speed up the wheel bearing's ageing process .

Only quality matters

The replacement of a wheel bearing is a hard and heavy work, requiring the use of special tools. Only a high-grade spare part of well-known brands is capable of withstanding the heavy forces in the long term. You should therefore never save on the wheel bearing. Even if a branded component costs slightly more, the considerably longer replacement interval is a sufficient reason not to use a cheap part.