The engine or gearbox mount is faulty or the mounting bolts are loose. This means that the power unit is subject to vibrations when the clutch is engaged.
The lining on the driven disk is burnt or hardened, i.e. there is no uniform friction between the clutch and the flywheel. This can happen, for example, if you tow another car over a long distance.
The pressure plate became deformed due to severe overheating, i.e. the friction surface became uneven.
In all cases, the clutch and driven disc must be removed to find the cause of the fault.
If the clutch fails while driving or no longer engages or disengages, you can continue driving at least to the nearest workshop or to your final destination. You can even change gears. If the clutch fails while the car is moving and the gear is engaged, and you need to disengage the gear, release the gas and shift the lever to neutral. If the gear is sticking, you can add a little gas until the shift lever is released.
To start moving without the clutch, proceed as follows:
1. Turn off the engine and engage first gear.
2. Engage the starter. The car will jerk forward until the engine speed matches the drive.
3. If the engine is cold, you need to warm it up first so that it doesn't stall right away. If you drive on a flat street in second gear, you can get to the nearest workshop.
4. If you want to try upshifting, start in first gear as described above and rev the engine to 1000 rpm. Release the gas pedal slightly and shift the lever to neutral. Release the gas pedal completely and push the lever to second gear. When the engine and gearbox rpm equalize, the gear will engage. If the time between engagements is too long, you will need to add gas again to engage the gear. Only perform upshifts at low speeds, engage second gear at 20 km/h, third at 25 km/h, fourth at 35 km/h. It is unlikely that you will reach fifth gear.
5. When downshifting, the RPM must be increased to enable the next gear to be engaged. Release the gas slightly, disengage the gear and gently press the gas pedal. At the same time, press the lever in the direction of the next lower gear. If the RPM is correct, the gear will engage immediately. Also, when downshifting, the driving speed must be reduced to keep the shifting under control. If there is a grinding noise, the shifting mechanism should be checked again. Thanks to the synchronization, the shifting is carried out easily.