Clutch Does not Disengage

Cause:

• Deformation during transport or installation Lateral runout of approx. 0.5 mm exceeded

Consequence:

• The specific lift on the pressure plate is no longer sufficient to ensure full disengagement

Please note:

Always check clutch disks for lateral runout before installation.

Cause:

• Lubrication instructions not followed during installation

Consequence:

• Clutch disk fails to slide freely on transmission shaft, jams. Clutch facing still contacts friction surface on flywheel. Grab can be evident in the early stages.

Please note:

Always use high-performance lubricant, SACHS no. 4200 080 050.

Cause:

• Transmission shaft and clutch hub forced together during installation

Consequence:

• Clutch disk jams instead of slides on transmission shaft.

Please note:

Center the clutch disk - using the right tools - during installation! Insert the transmission shaft carefully

Cause:

• Transmission shaft jammed against clutch disk hub during installation.
• Deformation due to severe overheating (blue discoloration of steel components).

Consequence:

• Prescribed lift on pressure plate is no longer sufficient to smoothly disengage clutch.

Please note:

Also causes drag due to insufficient lift on pressure plate.

Cause:

• Engine or transmission dropped with the transmission shaft still in the clutch disk hub. Fracture caused by lever effect
• Parallel or angular deviation

Consequence:

• Excessive lateral runout of clutch disk.

Cause:

• Clutch housing and crankcase flange not centered, wobble motion due to angular or parallel deviation
• Pilot bearing missing
• Transmission input shaft has excessive play or is not guided

Consequence:

• Hub jammed or tilted on transmission input shaft

Please note:

Can also cause noise.

Cause:

• Driving at high roll speeds in low gear with the clutch pedal depressed, clutch disk exceeds burst speed
• Selecting the wrong (too low) gear when downshifting

Consequence:

• Facing debris gets stuck in the flywheel or in the clutch pressure plate housing.

Please note:

The engine is not involved at all! Facing burst speed is around 1.7 to 2 times higher than the maximum engine rpm. Overheated facings may burst earlier.

Cause:

• Low-revving driving style. Driving in high gear at low speed and full throttle.
• Extreme irregular engine operation
• Worn joints in the driveline

Consequence:

• Fragments are thrown outwards and get stuck in the facings.

Cause:

• Extreme thrust load due to
  • Incorrect shifting
  • Improper towing maneuvers
  • Operational errors on the roller test stand
• Play in the driveline
• Deformation during installation

Consequence:

• Insufficient pressure plate lift.

Cause:

• Permissible release travel exceeded
• Incorrect disk installed

Consequence:

• Diaphragm spring drives clutch disk

Please note:

Also causes noise

Cause:

• Guide tube for the clutch release bearing bent
• Engine / transmission not correctly centered

Consequence:

• Continuous off-center clutch release bearing contact with the diaphragm spring tips exceeding the self-centering capacity will cause relative motion and therefore wear. This also applies to the release levers.

Cause:

• Clutch permitted to slip constantly
• Insufficient clamp force
• Problems with the release system, e.g. stiffness or lack of clutch play
• Contamination with oil or grease
• Excessive flywheel thickness

Consequence:

• Insufficient pressure plate lift.

Cause:

• Incorrect clutch pressure plate installed
• End plate / clutch pressure plate incorrectly positioned relative to locating pins on flywheel

Consequence:

• Housing deformed such that pressure plate has insufficient lift.

Cause:

• Transmission shaft jammed against clutch disk hub during installation.

Consequence:

• Serious damage leading to component failure.

Please note:

Multi-step torsional damping mechanisms have a complex, almost delicate structure. Handle with the utmost care during installation.