A worn clutch makes itself felt, first of all, when driving in the highest gear with a load. The engine runs at high speeds, but the driving speed does not increase.
Is the clutch worn?
1. Apply the handbrake to the machine and start the engine.
2. Engage 3rd gear, slowly release the clutch pedal and add gas.
3. With good handbrake and traction, the engine should slow down and almost stall.
4. If the engine runs without much change, then the clutch must be replaced, as the clutch clearance adjustment mechanism has fully exhausted its life.
Is the clutch disengaging correctly?
If scratching noises or crackling are heard during clutch operation, this means that the clutch is not fully disengaged - the driven disk is not completely released. To be sure that the problem is not in the gearbox, check with unsynchronized reverse:
1. Start the engine and let it idle.
2. Fully depress the clutch pedal, wait 3 seconds, then engage reverse gear.
3. If the scratching noises have not stopped, the clutch will not fully disengage.
4. Check the control automatics for serviceability.
5. Check again. If scratching continues, see table «Trouble-shooting» at the end of the chapter.