When one of the four hub bearings of the vehicle is damaged, you will hear a continuous buzzing sound in the car when the car is moving. This sound is not clear where it comes from. It feels like the whole car is full of this buzzing sound, and the faster the speed, the greater the sound. Here's how to judge:

Method one: open the window to listen to whether the sound comes from outside the car; 

Method two: after improving the speed (when the buzz is larger) will gear in neutral to let the vehicle taxi, observe whether the noise comes from the engine, if there is no change in neutral taxi hum that is mostly the wheel bearing problem; 

Method 3: temporary parking, check the temperature of the shaft is normal, the method is: use hands to touch the four wheels, the temperature of the general feeling about them are consistent (brake shoe, normal clearance, the temperature of the front and rear wheels is a gap, the front wheel is high), if feel difference may continue to slow traffic to the pit; 

Method 4: lift the car rises (prior to loosen the hand brake, idling), there is no elevator can jack rises one wheel, human fast four wheels, respectively, when there are problems of axle, it make a sound, like nothing else axle, using this method can easily distinguish which axle is have a problem. 

If the hub bearing is seriously damaged, it has cracks, pitting or ablation, and must be replaced. Grease is applied before installing the new bearing, and then it is installed in the opposite order. The replaced bearing must be flexible and free from clutter and vibration