When one of the four hub bearings of a vehicle is damaged, you will hear a continuous hum in the car while driving. It can't tell where it came from. It feels like the whole car is full of this hum, and the faster the car goes, the louder the sound is. The following is the judgment method:
Method 1: Open the window and listen if the sound comes from outside the car.
Method 2: Raise the speed (when the buzz is loud) and let the car slide in neutral gear to observe whether the noise comes from the engine. If the buzz does not change when the neutral gear glides, it is mostly the wheel bearing problem;
Method 3: Stop temporarily and check the temperature of the axle to see if it is normal. The method is to touch the four hubs with your hands and feel roughly whether their temperature is the same (when the gap between the front and rear wheels is normal, the temperature of the front and rear wheels is different, and the front wheels should be high). If the difference is not significant, you can continue to drive slowly to the maintenance station;
Method 4: Use the lift to lift the car (before releasing the hand brake and hanging the neutral gear). When there is no lift, the wheel can be lifted one by one with a jack. Manpower can rotate four wheels quickly. When there is a problem with the axle, it will make a sound, which is totally different from other axles. It is easy to distinguish which axle has a problem with this method. Chinese style
If there are cracks, pitting or ablation on the hub bearing when it is seriously damaged, it must be replaced. Before installing new bearings, grease is applied first, and then the bearings are assembled in reverse order. After replacement, the bearings must rotate flexibly and have no clutter and vibration.