拖拉机在行驶过程中 ,有时会突然自动停止行走 ,这是由于变速箱自动脱档所致。自动脱档的原因 :(1 )变速箱轴孔磨损使轴承与轴孔配合间隙增大 ,从而使轴产生轴向窜动引起脱档 ;(2 )齿轮啮合面严重磨损 ,致使机车自动脱档 ;(3)变速箱内的变速轴弯曲变形 ,使齿轮在轴上产生倾斜度 Tractor in the driving process, and sometimes suddenly stop walking automatically, it is due to the gearbox automatically off the file. The reasons for automatic gear off: (1) gearbox shaft hole wear so that the bearing and shaft hole with the gap increases, so that the shaft axial movement caused by gear; (2) gear meshing surface serious wear and tear, resulting in automatic removal of the locomotive ; (3) gearbox transmission shaft bending deformation, the gear in the shaft tilt