On the Jinma the shifter fork can be replaced pretty easily. The transmission cover comes off with a few bolts, it's above the oil line so you don't have to worry about the gasket. The fork itself is held on with a pin and it can be replaced with the transmission in place. So wipe the dirt off and pop the cover and see what's going on.
If the fork is broken you don't want to drive it, a broken off piece can really mess things up.