我处有一台手扶拖拉机在运输作业中载荷量大 ,工作正常。但在旋耕作业时一挡能正常作业 ,换二挡、三挡行走时 ,时有发生乱挡 ,且越来越严重 ,直至不能作业。修理工拆开变速箱并未查出故障 ,但装回后仍无法进行正常工作。只好再请修理工将齿轮、拔叉、拔叉轴、拔叉弹簧、钢球等 I have a walking tractor in the transport operations load, work properly. However, a rotary work can be a normal operation, for the second block, third block walking, sometimes disorder occurs, and more and more serious, until they can not work. The mechanic disassembled the gearbox and did not detect the problem, but still could not get the job done after it was installed. Had to ask the mechanic will gear, fork, fork shaft, fork spring, steel ball and so on