The suspension (mounting) of the car or gearbox is faulty, or the mounting bolts are loose. This means that the power unit begins to vibrate when the clutch is engaged.
The clutch slave disk linings are burnt or hardened, i.e. uneven friction between the clutch and flywheel is possible. If, for example, another car is towed over a long distance, this may happen, which will not be noticeable at first.
As a result, the pressure plate can become deformed due to the strong heat generation, i.e. the friction surface is no longer perfectly smooth.
In all cases, it is necessary to remove the clutch and driven disk to accurately determine the cause of the malfunction.
If the clutch fails while driving or the clutch no longer engages or disengages, you can still continue your journey to the nearest workshop or home. You can even shift gears in ascending or descending order. If the clutch fails while the car is moving with the gear engaged and you need to disengage the gear, you need to release the accelerator and switch the gearshift lever to neutral. If this does not work, you can give the accelerator a little until the lever is released. To move without a clutch, do the following:
Turn off the engine and engage first gear.
Turn on the starter. The car will start moving jerkily until the engine speed increases. If the engine is cold, it should be pre-warmed so that it does not stop immediately after starting. On a level road, you can start off in second gear and thus get to the nearest workshop.
If you want to shift into a higher gear, you need to start moving in first gear, as described above, and accelerate the engine to about 1000 rpm. Slightly release the gas pedal and pull the gearshift lever to neutral. Now release the gas pedal completely and press the gearshift lever towards the second gear position. When the engine and gearshift speeds match, the gear will engage. If the interval between shifts is too long, you need to give the gas a little again so that you can engage the gear. Shift into a higher gear only at low speeds, i.e. shift into second gear at a speed of about 20 km/h, into third gear at about 25 km/h, into fourth gear at 35 km/h. Fifth gear cannot be engaged.
When downshifting, the RPM should be increased so that the next gear can be engaged. Slightly release the "gas", disengage the gear and carefully press the "gas". At the right moment, press the gearshift lever to the position of the next lower gear. At the correct engine speed, the gear will be engaged without delay. When engaging lower gears, you must reduce the speed of the car accordingly to keep the shifting process under control. If there is a grinding noise, you must again control the shifting process. Thanks to the synchronizers, shifting is easy with careful handling of the gearshift lever and should not be particularly difficult.
It has been found that it takes a little practice to follow the above instructions to ensure the process goes smoothly.