The small loader cannot move forward or backward. First, check whether there is oil shortage in the gearbox of the small loader and whether the oil inlet pipe is blocked. Then check the gearbox oil pan of the small loader and the filter of the torque converter.

　　If it is found that there are metal fragments and other things in it, it can be sure that the parts in the clutch in the gearbox are damaged. If aluminum chips are found in the transmission oil pan and the torque converter filter of the small loader, it is certain that the roommate parts in the torque converter are damaged. At this time, it is necessary to remove and check the transmission and torque converter, and repair and replace the damaged parts.

　　To eliminate the above reasons, if the small loader is still unable to walk, it can be determined that the bolts around the second gear components in the gearbox are cut off, or the output gear of the intermediate shaft falls off, so that the power cannot be output. The elimination method is as follows: the 8-shaped end cover of the small loader gearbox can be disassembled, the second gear component can be taken out, and the cut bolt can be replaced. The material of this bolt is 40Cr, which must be subject to tempering treatment and can never be replaced by ordinary bolts.