Clutch - General Information and Component Inspection

All models equipped with a manual transmission use a single-plate dry-type clutch with a diaphragm spring. The hub of the friction (driven) disc has longitudinal splines that engage with the splines of the transmission input shaft. The friction disc and pressure plate are held in contact with each other by the force generated by the diaphragm spring of the pressure plate.

The clutch is released hydraulically. The release system consists of the clutch pedal, master cylinder with reservoir, connecting lines, and slave cylinder, which acts on the clutch release lever and release bearing.

When the clutch pedal is depressed, hydraulic pressure rises in the system and is applied to the outer end of the clutch release lever. As the lever rotates, its shaft fingers press against the release bearing, which moves and presses against the fingers of the diaphragm spring in the clutch cover assembly. The spring flexes, breaking contact between the pressure plate and the friction disc, which releases the driven disc.

When servicing the clutch, in addition to replacing components with obvious damage, perform the following preliminary checks (assuming the transmission is in good condition):

a) First check the fluid level in the clutch master cylinder (see Chapter Maintenance and Tune-up). If necessary, top up with the required amount of hydraulic fluid and carefully inspect the system for signs of leakage. If the master cylinder reservoir has been emptied, bleed air from the hydraulic circuit (see Bleeding Air from the Clutch Release Hydraulic System), then check clutch operation;
b) To evaluate clutch disengagement, start the engine at normal idle speed. Make sure neutral is selected and release the clutch pedal. Now depress the clutch pedal and, after waiting a few seconds, engage reverse gear. Shifting should not produce grinding or other abnormal noises, which strongly indicate a faulty driven disc or clutch cover assembly;
c) To check that the clutch fully disengages, apply the parking brake and start the engine. Holding the clutch pedal about 13 mm above the floor, shift the transmission between first and reverse. Interference when shifting the lever indicates a fault in the release mechanism components. Check the slave cylinder pushrod travel. With the clutch pedal fully depressed, the pushrod should extend noticeably; otherwise check the fluid level in the master cylinder;
d) Visually inspect the bushings at the upper end of the clutch pedal. Make sure there are no signs of binding or excessive pedal shaft play;
e) Get under the vehicle and make sure the clutch release lever is firmly seated on the ball stud of the ball joint.