Clutch: Description and Operation
ClutchThe primary function of the clutch is to couple and uncouple engine power to the transmission upon driver command.
^ The clutch is a single plate, dry friction clutch disc. The clutch disc has a splined hub (with integral torsional dampening springs) which attaches the clutch disc to the input shaft.
^ Engine output is coupled to the input shaft by the friction existing between the clutch disc facings and the flywheel/clutch pressure plate assembly. The extent of this friction is directly related to the composition of the facing material and the magnitude of the clamping force exerted by the clutch pressure plate. These factors limit the amount of torque that can be transmitted without slippage.
^ The clamping force is obtained from a diaphragm spring contained within the clutch pressure plate assembly. This force is developed during the attachment of the clutch pressure plate to the flywheel.
^ The clutch system is disengaged when the clutch pedal is depressed and engaged when the clutch pedal is released. This displacement removes the spring load from the clutch pressure plate and eliminates the coupling friction between the engine and the transmission.
^ When the clutch pedal is depressed, a cable connected to the clutch release lever, hub and bearing actuates the clutch pressure plate diaphragm spring, releasing pressure on the clutch disc. This eliminates the engagement between the transmission and the engine.
Special Tools:
Special Tools:
Clutch Controls
The clutch control system engages and disengages the clutch. The clutch control system disengages the clutch when the clutch pedal is depressed and engages the clutch when the clutch pedal is released. Clutch pedal motion is transmitted by the clutch release lever cable to the clutch release lever. The clutch release hub and bearing engages the clutch pressure plate diaphragm spring, releasing the pressure on the clutch disc which in turn disengages the transmission from the engine.
The clutch adjusts automatically to compensate for clutch disc wear. The clutch linkage is self-adjusting.
The Clutch Pedal Position (CPP) switch prevents the starter motor from engaging unless the clutch pedal is depressed all the way to the floor. The switch plunger is contacted by the clutch pedal and extends as the clutch pedal is pressed. The clutch pedal position switch is electrically connected in line with the ignition switch and the starter motor relay coil. The CPP also turns off the speed control when the clutch pedal is depressed.