Under the action of long-term torsional fatigue and impact force, the axle of the automobile is prone to failures such as bending, twisting and breaking, and spline tooth wear or skew. The most common faults in automotive axles are as follows: First, the bending of the half shaft, at this time the owner can put the half shaft on the V-shaped iron or on the lathe, check the neck of the oil seal with a dial gauge, the pointer should not exceed 5mm, otherwise it should be cold-pressed and straightened. . Second, the half shaft flange plane should be perpendicular to the center line of the half shaft. In the case where the semi-axis has no q-curve deformation, the basin is measured at the edge of the flange with a dry minute meter, and the pointer yaw cannot be larger than 0.2 mm, otherwise it should be corrected by buffing. Third, the half shaft spline tooth and the gear spline groove matching clearance can not be greater than 0.75mm, the half shaft spline tooth skew should not be greater than 1.00mm, otherwise it should be replaced with new parts or surfacing repair. Fourth, the wear of the half shaft oil seal neck can not be greater than 0.3mm, otherwise surfacing or chrome repair. 5. If the half shaft breaks or has cracks, it should be replaced with new ones.