When the gearbox is shifting, the gear cannot be disengaged. The reasons are:

(1) The piston ring swells to death;(2) The clutch friction plate is burnt;(3) The clutch return spring is invalid or damaged;(4) The oil return tube is blocked.

The gear has been engaged, but the loader is running weak and even unable to start. Reasons are:(1) The friction lining is severely worn and the clearance is too large;(2) The clutch automatic emptying valve is not tightly sealed and the pressure drops

(3) The shift control valve pipeline is blocked;(4) The shut-off valve cannot be returned;(5) The positioning spring of the variable speed valve is fatigued or broken, and the steel ball jumps;(6) The clutch piston ring and the sealing ring are severely worn and leaking.