Indicator:

Slipping clutch/Engagement and Dis-Engagement Problems

Cause:

1. Bell housing has not been degreased and cleaned. Poor installation of the new clutch. The new clutch disc has not worn but fibres 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 free from old fibres, dirt and grease when installing new clutch.
2. This problem is common in 4 wheel drive vehicles when an inspection cover or a clutch fork cover boot has not been Inspected for re-use or replaced when installing a new clutch.

Effect: 

Worn clutch disc facing fibres and/or dirt lodged between diaphragm spring and clutch cover housing causing loss of cover clamping force.

Action:

1. Ensure the bell housing and back of the engine are thoroughly degreased and cleaned of foreign material before installing a new clutch.
2. Ensure inspection locations are sealed correctly with any boots thoroughly inspected for re-use and if necessary replaced. (Note: These problems are common on farm vehicles, vehicles travelling on sand and 4x4 recreational vehicles.)

» Link to Guide

Indicator:

Loss of dive/Poor clutch performance/Noisy in operation

Cause:

1. Engine to gearbox dowels missing or damaged
2. Gearbox and/or engine mounting face damaged or have high levels of contamination
3. Obstructions between engine and gearbox mounting face preventing the gearbox to be flush to the engine when mounted.
4. Missing/damaged or incorrectly torqued gearbox mounting bolts
5. Clutch disc overload (Changing from 5th to 2nd at high speed)
6. Excessive RPM load (Launching the vehicle at high RPM)

Effect:

Clutch disc damper springs have become dis-lodged and stop pins are damaged

Action:

1. Replace clutch kit
2. Replace gearbox dowels
3. Ensure the gearbox and engine mating surfaces are free from contamination.
4. Ensure there are no obstructions between engine and gearbox when final torqueing of the gearbox mounting bolts
5. Replace worn or damaged gearbox mounting bolts if necessary
6. Driver education

» Link to Guide

Indicator:

Loss of dive/Poor clutch performance

Cause:

1. Engine to gearbox dowels missing or damaged
2. Gearbox and/or engine mounting face damaged or have high levels of contamination
3. Obstructions between engine and gearbox mounting face preventing the gearbox to be flush to the engine when mounted.
4. Missing/damaged or incorrectly torqued gearbox mounting bolts

Effect:

Clutch disc failure due to mis-alignment (gearbox centre off-axis to crankshaft)

Action:

1. Replace clutch kit
2. Replace gearbox dowels
3. Ensure the gearbox and engine mating surfaces are free from contamination.
4. Ensure there are no obstructions between engine and gearbox when final torqueing of the gearbox mounting bolts
5. Replace worn or damaged gearbox mounting bolts if necessary

» Link to Guide