It is quite difficult to diagnose the health of a gearbox by the noise it makes. If you are unable to pinpoint the source of the noise, contact a qualified technician.
Cause of failure (Remedy)
Noise in the gearbox. Noise decreases or disappears when the clutch is depressed:
- - Insufficient oil level in the gearbox housing (Check the level, add oil if necessary, check for leaks, clean or replace the breather if necessary)
- - Poor oil quality. Water has entered the oil (when water enters, the oil will form a white emulsion) (Change the oil)
- - Worn or damaged bearings, gear teeth (Replace worn bearings, gears)
Gears are difficult to turn on, there are no extraneous noises:
- - Looseness of the shift forks on the stems due to loosening of the stop bolts (Tighten the bolts of the shift forks on the stems)
- - Burrs on the teeth of the sliding sleeves of the synchronizers (Cut off the burrs with a needle file)
- - Wear on the pin holes on the bottom of the shift lever (Replace the bottom of the lever)
- - Clutch won't turn off (Repair clutch)
Transmissions spontaneously turn off:
- - Damaged or worn splines on the clutch, gear or synchronizer hub (Replace defective parts)
- - the bolts of the gearbox to the clutch housing and / or the clutch housing to the engine are not tightened (Tighten the mounting bolts)
- - Lost elasticity or collapsed detent springs, worn rods (Replace defective parts)
Noise, crackle, squeal of gear couplingswhen the gear is engaged:
- - Clutch does not fully disengage (See Clutch Troubleshooting)
- -Low oil in gearbox housing (Add oil, check for leaks, clean or replace breather)
- - Worn or deformed shift synchro ring (Replace ring)
Oil leak:
- - Wear of cuffs (Replace cuffs, if necessary, clean or replace the breather of the gearbox)
- - Strong wear, nicks on the surfaces of the shafts on which the edges of the cuffs work (Smooth out minor damage - with fine-grained sandpaper and polish)
When installing a new cuff, you can slightly underpress it, avoiding distortion (if necessary, placing distance washers up to 1 mm thick under it) so that the edge of the cuff works on the unworn part of the shaft. In case of significant damage, replace the shafts and cuffs
- - Increased pressure in the gearbox due to clogged breather (Clean or replace the breather of the gearbox)
- - Loose gearbox housings, front cover or shift lever housing, gaskets damaged (Tighten threaded connections) Replace gaskets (sealant can be used when installing them)
- - Drain and fill plugs loose (Tighten the plugs, you can put them on the sealant)