TECHNICAL KNOWLEDGE
The Right Knowledge for the Right Application
Clutch operation, installation guidance and common issues.How does a clutch system work?
The flywheel, disc, pressure plate and release bearing work together to control power transfer between the engine and transmission. Pressing the pedal makes the release bearing act on the diaphragm spring, removing clamping force from the disc.
Frequently Asked Questions
Clutch judder+
- Burnt or oil-contaminated clutch disc
- Circular wear on the disc surface
- Excessive clutch fork or pivot wear
- Damaged flywheel surface
- Input-shaft misalignment
- Overheated pressure surface
- Incorrect seating against the flywheel
- Bent diaphragm fingers during installation
- Cover dropped during transport or installation
- Bolts not tightened evenly in a cross pattern
- Gearbox weight carried by the disc hub during installation
Clutch fails to disengage+
- Insufficient hydraulic flow from the clutch master cylinder
- The slave cylinder cannot transmit sufficient force to the fork
- Wear on the clutch fork tip or pivot ball
- Damage to the pressure plate support straps
- Damage to the input-shaft cover
Clutch slipping+
- Pressure plate not seated correctly on the flywheel
- Oil contamination on friction surfaces
- Master or slave cylinder remaining actuated
- Release bearing reaching the end of its service life
- Burnt friction surfaces caused by riding the clutch or using an unsuitable gear
- Oil leakage from the engine or transmission
Clutch noise+
- Excessive wear on diaphragm spring fingers
- Gearbox weight carried by the disc hub during installation
- Unsuitable lubrication in the system
- Excessive clutch slipping
- Keeping a foot on the clutch pedal after shifting
- Operating the vehicle in an unsuitable engine-speed range
Stiff clutch pedal+
- Incorrect bearing or pedal clearance
- Unsuitable lubrication or excessive load
- Master cylinder failure
- Hydraulic lines losing their properties
- Worn input-shaft cover
- Clutch fork or pivot wear
- Slave cylinder failure
- Bolts not tightened evenly in a cross pattern
What is a clutch and how does it work?+
The clutch controls the connection between the engine and transmission. It enables smooth pull-away and allows gears to be changed quietly and progressively.
Pressing the pedal makes the release bearing act on the diaphragm spring, releasing the disc and interrupting torque transfer. Releasing the pedal clamps the disc between the flywheel and pressure plate so power transmission resumes.
What are the main components of a clutch system?+
- Flywheel
- Clutch disc
- Clutch cover / pressure plate
- Release bearing or hydraulic concentric slave cylinder
The flywheel carries engine rotation, the disc transfers torque to the transmission input shaft, the pressure plate supplies clamping force, and the bearing converts pedal input into release movement. Damper springs in the disc help absorb shock and vibration.
Why and how should the hub splines be greased?+
Correct, limited lubrication lets the disc hub move freely on the transmission input shaft and reduces fretting corrosion. Apply only a thin film of grease suitable for high temperature and surface pressure to the hub splines and input shaft.
Move the disc back and forth on the shaft to distribute the grease, then remove all excess. Too much grease can reach the friction linings through centrifugal force and cause judder or slip. Before installation, also check disc lateral runout; values above 0.5 mm may cause drag.