Slipping occurs when the disc fails to rotate at the same speed as the driving members when the clutch is engaged. Essentially it is when the pressure plate fails to hold the disc tight against the face of the flywheel.

Causes of slip:

  • Grease and/or oil on the disc
  • Driver resting foot on clutch pedal causing bearing to ride on pressure plate and keeping plate in slightly release position.
  • Faulty hydraulic hindering the pressure plate from fully releasing.

Check clutch master cylinder and slave cylinder for any signs of leaking or failure. Hydraulics could have seized the keeping pressure plate in slight release.

  • Flywheel improperly resurfaced or incorrect step.
  • Vehicle is overpowering the clutch.
  • Damaged or bent clutch disc
  • Clutch disc has broken or missing friction material.
  • Friction material of the clutch disc is glazed from overheating.
  • Improper or damaged release bearing.
  • Clutch assembly not fully seating in – improper break in procedure

Slipping related to clutch adjustment

  • Normal wear of the clutch lining causes the free travel of the clutch linkage to decrease, creating the need for adjustment.
  • Improper clutch adjustment can cause slippage by keeping the release bearing in contact with the pressure plate which can cause the pressure plate to be in a slightly released position.
  • Binding linkages prevents pressure plate from exerting full pressure against disc. Inspect release mechanisms for rusted, bent, misaligned, sticking, or damage components. Wiggle release fork to check for free play. Also broken motor mounts can causing binding linkages from excessive engine movement.