Clutch in engaged position (with the pedal released) should not "slip" and transmit torque from the engine to the transmission without loss, and when the clutch pedal is pressed, completely disconnect the transmission from the engine. The clutch engagement should be smooth, without jerks.
Note. The clutch check is shown using a car with a manual transmission (MT) as an example. The clutch check on a car with an automated transmission is shown in the section "Automated transmission - technical condition check".
Sequence of execution
1. Prepare the car for work (see "Preparing the car for maintenance and repair").
2. With the engine not running, press the clutch pedal several times. We make sure that there are no jams in the clutch release drive mechanism, and that there are no creaks, knocks or other extraneous noises.
3. Start the engine. If you hear a whining sound coming from the clutch housing that gets louder when you press the clutch pedal, the clutch release bearing is most likely worn out.
4. With the engine running, press the clutch pedal all the way down and engage the gear. The switch should be easy to turn on, without any crackling or crunching sounds. If you hear a crackling sound when engaging gears and it is difficult to disengage, this means that the clutch is not disengaging completely. We bleed the clutch release hydraulic drive. If there is no air in the drive, the defect may be caused by a malfunction of the clutch master cylinder, clutch slave cylinder, wear or reduced elasticity of the diaphragm spring.
5. With the engine running and first gear engaged, gradually releasing the clutch pedal, check the smoothness of the clutch engagement, the absence of jerks and extraneous sounds when starting off. Jerks and rattling when the clutch is engaged can be caused by oiling or warping of the clutch discs, or destruction of the torsional vibration damper.
6. While driving in third gear, sharply press the gas pedal. If the engine speed increases quickly and the car accelerates sluggishly, the clutch is slipping. This is also indicated by the appearance of a burning smell in the cabin, emitted by the highly heated friction linings of the driven disk. To eliminate this malfunction, it is necessary to replace the clutch.
If the above signs of malfunction are not detected during the clutch diagnostics, the clutch is in good technical condition.