1. Abnormal sound characteristics of disc brake: When the vehicle is driving on a flat road at low speed, it makes intermittent and irregular "quack" sound at the axle, which will be slightly aggravated when the vehicle speed increases, but it will not change when going up, down and turning; When driving on uneven roads, the noise is aggravated, and the noise of stepping on the brake pedal with your feet is reduced or disappeared. When stopping for inspection, you can hear abnormal noise by turning the wheel back and forth. Reason: This is because the brake shoe support plate, damping spring plate or guide plate of disc brake are damaged, deformed and fall off, which makes the gap between brake shoe and caliper support frame increase and collide with each other to make a sound. You can go to the maintenance station to repair the deformed parts and replace the parts.

2. Abnormal noise characteristics of the front suspension ball head: When the vehicle is driving at low speed on uneven roads, the front axle will make an uninterrupted "click" sound. The worse the pavement quality, the greater the noise, and the noise will increase with the increase of vehicle speed. After parking, the front of the vehicle will shake left and right, which will produce abnormal noise. If the vehicle is driving on a flat road, the front axle will have intermittent and irregular abnormal noise, such as the impact of steel fracture. Cause: The clearance between the ball head and the ball head seat becomes larger and the looseness is serious. Because the tee is sealed and cannot be disassembled, it can only be replaced in the maintenance station.

3. Abnormal sound characteristics of the front wheel shock absorber: On the flat road, the "cooing" sound in front of the vehicle can be heard slightly, and the sound is intensified when turning sharply. When stopping for inspection, press the front of the vehicle hard to make it rebound up and down, resulting in abnormal sound. The greater the strength, the greater the noise. At the same time, I feel that the vehicle is inelastic and not soft. Cause: The vehicle usually runs on a bad road and is not properly maintained, resulting in oil leakage and damage to the shock absorber. At the repair station, this situation depends on the severity of the damage to be repaired or replaced.

4. Abnormal noise characteristics of transmission shaft universal joint: If the front drive constant velocity universal joint is faulty, the vehicle will make abnormal noise when driving, especially when turning or accelerating sharply. If there is something wrong with the universal joint equipped with the cross shaft, when the vehicle is driving at a low speed, the noise similar to dry friction can be heard under the vehicle body, and the noise is obvious when the vehicle speed is increased, but the noise will not disappear when the vehicle speed is reduced. Cause: Abnormal sound of constant velocity universal joint is caused by excessive clearance or hairpin. The main reason for the abnormal sound of the universal cross shaft is that there is no lubricating device or the maintenance is not timely. In this case, you should go to the maintenance station to apply grease or repair.