How to maintain hub bearings?

Inspection of hub bearings

• To determine if the bearings of a vehicle are damaged, the following two methods can be used:

Place the vehicle on a lift and rotate the wheels forcefully. Observe whether the wheels rotate smoothly, if there is any sticking phenomenon, and assess whether the drag torque of the wheels is normal. If the ball bearings are poorly lubricated or deformed, it will cause sticking or an increase in the drag force.

• During normal vehicle operation, pay attention to whether any abnormal sounds are coming from the wheel direction. If the ball lubrication is poor, the first problem that occurs is an abnormal sound, and the speed is fast with a loud noise, while the speed is slow with a quiet noise. If there is no abnormal sound, generally, there will be no problem.

In addition, since the majority of the wheel speed sensors' signal sources (magnets or magnetic maps) are integrated in the bearings at present, if there is a problem with the wheel speed signal, the instrument panel will display a fault code, and the ABS fault light will be illuminated, as shown in the following figure.

So, if the ABS fault indicator keeps flashing, it could also be that the magnetic poles of the bearing have been damaged.