When a car is running, the gear lever automatically jump back to the phenomenon known as neutral transmission gear jumping. The reasons for this phenomenon are as follows: (1) the adjustment of the control rod of the Baotou North running heavy steam parts is not correct, and the gear or the teeth of the cog teeth are worn into conical. (2) the wear and tear of the transmission shaft, bearing or gear are loose and the axial clearance is too large, so that the shaft is moving when the shaft is rotated. (3) the groove of the shift fork shaft and the position ball are badly worn, or the position ball spring is too soft. (4) the gear synchronizer of Baotou North rush parts is worn or damaged, and the gear shift is bending, and the gear shift rod is worn seriously. The methods of eliminating this kind of fault are: (1) when a file is found, the gearshift is still hung in the gear and the engine is extinguished. Check whether the correct adjustment of shift control mechanism; the remove transmission cover check gear and synchronizer; check the Baotou beiben accessories bearing wear loose, the shift fork is deformation or wear, such as the gap is too large to be a shift fork welding deformation correction should be thickened, fork. (2) gear wear into conical should be replaced. The excessive movement of the front and back of the shaft should be adjusted. (3) the gear shift mechanism is not well positioned, and it must be removed from the gear shaft to repair or replace the unqualified parts. (4) the synchronizer is badly worn and should be replaced. The shift fork bending and gear shift rod wear seriously, and correct welding repairs or replacement of new products should be carried out.