Automatic deviation of the agricultural transport vehicle will not only make the driver fatigued, but also cause traffic accidents. For this reason, once the agricultural vehicle runs automatically, it should be repaired in time. Causes of side-tracking are: Over-tightness or jamming of the wheel hub bearing on one side causes the rolling resistance of the wheel to increase: After a certain distance has been travelled, touch the bearing at the hand, and if it feels hot, it means the bearing is too tight or stuck. The bearing tightness should be adjusted. The method is: lift the front axle, screw the bearing nut to the end, and then return 1/6-1/8 turn, and then wear the split pin. The leaf spring on one side breaks and causes the locomotive to tilt toward the side: check whether the leaf spring breaks, deforms, dislocates or looses the bolt and replace it if necessary. The load-bearing capacity of leaf springs on the left and right sides are inconsistent: If the leaf springs on the two sides have different stiffnesses, different arcs, and different bearing capacities, the locomotive will be tilted to the side where the load resistance of the leaf springs is weak. Should be replaced. Front wheel positioning asymmetry: If the steering trapezoid is not equal, the left (right) knuckle shaft is bent and deformed, and the knuckle shaft and the sleeve fit with the clearance of the steering knuckle axis. Should be corrected and repaired. Front axle, frame deformation: should be corrected. Left and right tire pressure is not equal: It should be full of air, and keep the same tire pressure. Unbalanced cargo: It should be loaded correctly.