Make sure the cables move freely (are the bushings of the shells in order, are there any loose shells, are the passages through the bulkhead shield in order, etc.), for example, due to previous work in the engine compartment (incorrect installation).
If there is no damage: correct the cable route. If damaged: Replace shift lever housing.
Check that there is no increased play in the gear lever (in gear shift direction).
From the side of the gear lever housing:
- no backlash of the cable sheath;
- lack of play of the ball end of the cable (in gear shift direction).
From the gearbox side:
- no backlash of the cable sheath;
- lack of play of the ball end of the cable (in gear shift direction);
- lack of play in the support (rubber deposition indicates bearing failure).
If play or any faults are found, replace the shift lever housing. If the gearshift drive is OK, check the engine and transmission suspension mounts and the tie rod (absence of breakages, damages, reliable tightening of fasteners, correct position, etc.).
If a problem is found, replace the damaged swing arm or tie rod.
Check the silent blocks of the engine and gearbox suspension mounts and jet thrust (absence of breaks, damage, correct position, presence, etc.).
If a malfunction is found, replace the damaged silent block. Check the nuts on the rear end of the input shaft (1) (only for gearbox type J).
If the vehicle has a J-type transmission and if only 5th gear disengages spontaneously: Replace the 5th gear assembly, gear bushing and fork.
If the nut is good, remove and open the gearbox.
Check Fasteners (presence, absence of jamming, etc.) (only for type J gearboxes).
If the latches are OK, replace the appropriate gear assembly (gear, clutch, hub, synchronizer rings and yoke).