Clutch Cover Slipping

Slipping clutch and clutch drag.

  • CAUSE
    • Bell housing not degreased and cleaned. Careless installation of new clutch.

      The new clutch disc has not worn but the fibres that have become lodged in the new clutch cover are that of the previously worn clutch. It is a requirement due to ventilation designs that the bell housing area be free from old fibres, dirt and grease when installing new clutch.
    • This problem is common in 4 wheel drive vehicles when an inspection cover or a clutch fork cover boot has not been replaced when installing a new clutch.
  • SOLUTION
    • Ensure bell housing is thoroughly degreased and clean of dirt and fibres before installing new clutch.
    • Ensure inspection locations and boots are replaced, tightened and well located.

      Note: These problems are common on farm vehicles, vehicles travelling on sand and 4X4 recreational vehicles.

1. Hold down bolts still in pressure plate assembly. 2. Unable to adjust. 3. Will not transmit power.

  • CAUSE
  • Clutch cover pressure plate assembly hold down bolts to assist ease of installation not removed.

  • SOLUTION
  • Remove hold down bolts.

  • NOTE
    • Do not remove clutch lever adjustment nuts.
    • (Common in Japanese trucks}

Engine revving when power applied during acceleration/will not transmit power. Evidence of oil contamination on cover assembly.

  • CAUSE
  • Clutch cover pressure plate assembly contaminated with oil.

  • SOLUTION
    • Rectify oil leaks.
    • If re-using a new cover that has been contaminated with oil, degrease the cover assembly and lightly lubricate diaphragm pivot rings before re-installing with light base oil.

Warped clutch cover pressure plate assembly casting.

  • CAUSE
  • Only clutch disc was replaced which caused a vacuum not allowing the clutch disc to separate from the clutch cover pressure plate assembly casting, when clutch is in disengaged position.

  • SOLUTION
  • Always replace clutch disc/clutch cover pressure plate assembly and clutch thrust release bearing when replacing clutch system.