Analysis of after sales problems of automobile drive axle

At present, in the after-sales of drive axle, we often receive many after-sales problems from customers. The following analyzes the after-sales problems of drive axle in terms of abnormal noise, heating, oil leakage, crack and fracture.

1. Abnormal noise of drive axle

The drive axle is composed of the main reducer and the wheel side system. There are many quality points to be controlled in the assembly process. Therefore, in the process of driving, if the drive axle makes abnormal noise, it should be stopped immediately for inspection. The causes of abnormal noise of drive axle are different, which should be judged according to different manifestations. When the car is running normally, there is no obvious noise, and it makes abnormal noise when turning. It is obvious that the damage or burning of the differential between the wheels leads to the poor meshing of the planetary gear of the differential and the axle gear, resulting in abnormal noise. Moreover, when the meshing sleeve of the inter wheel differential is loose, it will produce a collision sound, and when the meshing sleeve of the inter axle differential moves, it will also produce a collision sound, which is generally irregular mechanical collision sound. When the passive gear produces continuous abnormal noise, it is necessary to consider whether the gear meshing clearance is too large or poor meshing. Generally, the active and passive gears are grinded in pairs, so when they are replaced, they must be replaced in pairs and assembled together. Bearing looseness, loose frame or fixed bolt looseness, gear damage, etc., will also have abnormal noise, need timely detection and maintenance.

2. Overheating of drive axle

The overheating phenomenon of drive axle refers to when the temperature of main bevel gear bearing seat and hub bearing seat is too high after driving a certain distance, which is called overheating. The temperature of the main reducer shall not be higher than 120 ℃, and the temperature of the wheel edge shall not be higher than 90 ℃. The infrared thermometer can be used to measure the temperature 10-15cm away from the axle housing. The main reducer is located at the input end housing or the rear cover of the axle housing, and the wheel edge is measured at the end cover of the wheel edge. For the overheating phenomenon of brake drum, because the heat dissipation condition of brake drum itself is poor, frequent braking will make it overheat, which will lead to crack of brake drum for a long time. Therefore, it is recommended to use engine exhaust braking when going downhill for a long distance, so as to avoid frequent service braking as far as possible and prevent overheating phenomenon of brake drum. General drive axle overheating may have three reasons: bearing preload is too large, too much or too little lubricating oil. When the bearing preload is too large, it will affect the normal rolling friction between the inner and outer rings of the bearing and the rolling element, so as to overheat the bearing; When there is too much lubricating oil, there is no space in the whole lubricating chamber to dissipate the heat, so that the overall temperature of the lubricating oil rises, resulting in overheating; When there is a lack of oil, if the parts are not lubricated properly, the parts will overheat. When the oil seal of the axle shaft is damaged, the gear oil will run into the axle box, so that the wheel reducer can not be lubricated, thus generating heat.

3. Oil leakage of drive axle

For the drive axle oil leakage problem, there are many locations, and the reasons are different, which are generally divided into the following aspects: oil leakage caused by oil seal or seal ring failure, oil leakage caused by joint surface, oil leakage caused by axle housing weld, and oil leakage caused by sand holes in castings. When the flange oil seal, hub oil seal and O-ring of the differential are damaged or worn, oil leakage will occur. It is necessary to check the oil leakage position in time for repair and replacement. There are joint surfaces between main reducer and box cover, joint surfaces between main reducer and axle housing and joint surfaces between shaft head and end cover on the whole bridge. Attention should be paid to joint surface protection during maintenance, and joint surface scratches and bumps should be repaired in time, otherwise joint surface oil leakage will be caused. For the punching and welding of the axle housing, there are many welds on the axle housing. When the load of the axle housing is large, the stress of the weld is concentrated, resulting in cracks and oil leakage. For the cast axle housing, the casting defects such as sand hole and shrinkage cavity will also lead to oil leakage.

4. Crack and fracture of drive axle

The crack and fracture of drive axle usually occur at the position of the spring seat and the flange of axle housing. Due to the stress concentration in this part, fatigue crack and fracture will occur under the long-term alternating load of axle housing. Cracks often occur in the middle part of the bottom of the axle housing, because the ground clearance is the smallest. When driving on some roads with poor road conditions, they are often collided or scratched by large stones on the road surface, resulting in cracks.

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