DEFINITION: The clutch does not engage completely after the pedal is released, after shifting gears, or the clutch slips during maximum engine loads, such as climbing hills or high vehicle speeds. Clutch slipping is identified by increase in engine RPM without increase in vehicle speed.

Review the Symptoms - Clutch and perform the necessary inspections.

Incorrect clutch pedal height, not allowing the clutch master cylinder to return

Clutch pedal return spring is broken or missing

Replace the clutch pedal return spring.

Clutch pedal is binding or sticking

Clear away any items that may be contacting the pedal.

Clutch pedal bushings are seized or worn

Replace or repair the clutch pedal assembly.

Clutch housing lever and cross shaft binding

Lubricate the cross shaft and bushings.

Clutch clevis pins or external linkage seized or binding

Lubricate the clutch clevis pins and linkage.

Release bearing locknut loose

Adjust the release bearing length and tighten the locknut. Refer to Clutch Assembly Adjustment .

Clutch master cylinder binding or seized

Replace the clutch master cylinder.

Clutch actuator cylinder binding or seized

Replace the clutch actuator cylinder. Refer to Clutch Actuator Cylinder Replacement .

Kinked or damaged clutch hydraulic pipe or hose

Repair or replace the clutch hydraulic pipe and hose as necessary.

Grease or oil contamination of the clutch disc

1. Repair the source of the oil leak.
2. Repair the source of the grease leak.
3. Clean the contamination from the clutch components.
4. If contaminates cannot be removed, replace the clutch assembly. Refer to Clutch Assembly Replacement .

Worn or damaged flywheel

Replace the engine flywheel. Refer to Engine Flywheel Replacement in Engine Mechanical - 7.8L, or to the Caterpillar engine service manual.

Worn clutch disc facing

Replace the clutch assembly. Refer to Clutch Assembly Replacement .

Burnt or glazed clutch discs

Replace the clutch assembly. Refer to Clutch Assembly Replacement .

Input shaft splines worn

Replace the input shaft. Refer to Transmission Disassemble and Input Shaft Assemble Manual Transmission - MLD6Q Isuzu or the transmission manufacturer service manual.