Troubleshooting the clutch system

Clutch slipping

Cause	Correction

Clutch contact pressure insufficient.	Replace pressure plate
Clutch plate worn beyond minimum thickness of 7.5mm (0.295")	Replace clutch
Clutch plate contaminated with oil	Replace faulty crank or input shaft seal, clean or replace clutch
Clutch was overheated	Replace clutch

Clutch grabs

Cause	Correction

Clutch plate run-out in excess of 0.5mm (0.020")	Replace clutch
Clutch plate contaminated with oil	Replace faulty crank or input shaft seal and replace clutch
Release pressure one sided	Check release lever
Pressure plate pressing unevenly	Replace pressure plate
Crankshaft not aligned with transmission input shaft	Check centering surfaces on engine and transmission.
Engine or transmission mounts faulty.	Replace effected mounts

Clutch fails to release

Cause	Correction

Drive plate wrenched excessively or clutch plate broken	Replace clutch
Drive plate lateral run-out exceeds 0.5mm (0.020")	Straighten or replace clutch
Clutch plate rusted on flywheel	Resurface flywheel and clean or replace clutch
Drive plate seized on transmission input shaft	Replace clutch and clean and lube or replace input shaft
Pilot bearing in crankshaft bad	Replace pilot bearing
Air in hydraulic system	Bleed clutch
Tangential leaf springs of clutch bent	Replace clutch

Clutch noise

Cause	Correction

Clutch and/or pressure plate out of balance	Replace clutch
Broken damper springs	Replace clutch
Clutch release bearing faulty	Replace bearing
Pilot bearing faulty	Replace bearing
Clutch rivets loose	Replace clutch
Input shaft bearing faulty	Replace input bearing

E30 M3 Repair Manual V2.7. Copyright Š1999-2001 Koala Motorsport & Brett Anderson