Causes of damage to the rear axle shaft of a car

The rear axle axle is the partial speed axle that drives the wheels of the car, and is located in the axis of the rear axle. The inner end of the half shaft spline shaft and the differential half shaft gear spline sleeve set, the outer end flange of the half shaft and the wheel are fastened and assembled with studs, nuts and tapered bushings. The two half shafts can be driven at the same speed or at different speeds under different working conditions during transmission. Abnormalities in the rear axle housing, differential, wheels, etc. will affect the normal transmission of the axle shafts, wear and break the axle shafts, and even cause unpredictable losses to the vehicle. In addition to the overload of the vehicle and the increase of the rear transmission load caused by the driver's careless manipulation, the damage of the rear half shaft of the automobile has the following aspects:

(1) The inner end of the half shaft is damaged.

①The keyway of the spline shaft is tapered along the groove tooth length, steps, tooth surface deformities, etc., due to the looseness of the side gear bearing hole of the differential case and the side gear, the differential bearing is loose, and the rear wheel bearing is loose. Wait.

② Wear of the journal at the inner end of the axle shaft and the appearance of grooves on the axle surface are due to the looseness of the axle gear bearing hole of the differential case and the axle shaft, and the damage of the differential bearing.

(2) The middle part of the semi-axle is bent and abraded, and the hair surface of the shaft is in contact with the inner wall of the rear axle steel pipe. This is due to the deformation of the rear axle housing, cracks, the bending of the rear axle steel pipe, the loosening of the steel pipe and the rear axle housing, etc., making the rear axle housing The axis of the rear half shaft is offset.

(3) Cracks and breaks occurred in the middle part of the axle shaft and the root of the flange. Except for the forging and pressure scars of the original axle shaft during the manufacturing process, it was mainly due to the deformation and bending of the rear axle housing, the loosening of the steel pipe and the rear axle housing, and the loosening of the rear wheel bearing. The wide swing is so poor that the semi-shaft swings abnormally during transmission.

(4) The damage to the half-shaft flange stud with nut and tapered bushing is due to the deformation and bending of the rear axle housing, the bending of the half-shaft, and the looseness of the rear wheel bearing. The main reason is that the tapered bushing is not installed, or Ah If the hub is too small or too short, the flange studs with nuts and the hub are subjected to excessive force from the direction of rotation, and the screw holes on the flange plate and the hub socket holes are worn and enlarged, the threaded holes of the studs become loose, and the flanges The contact surface between the disc and the wheel was worn, and even all bolts were cut off. Damage to these parts of the semi-axle flange will often increase the transmission void of the semi-axle and cause the semi-axle to break.

The new marks on the broken and damaged part of the half shaft are caused by excessive or too strong transmission load, and the half new and half old marks on the broken part are cracks in the half shaft, and the cracks gradually expand and cause the fracture.