Clutch: Description and Operation

CLUTCH
DESCRIPTION - MECHANICAL

2.0L:

PL vehicles with a 2.0L engine use a modular clutch assembly (Fig. 1). The clutch is located between the engine and manual transaxle in the transaxle bellhousing. The 2.0L clutch system consists of the following components:
- Flywheel
- Clutch Disc
- Pressure Plate
- Diaphragm Spring
- Cover

MODULAR CLUTCH:

MODULAR CLUTCH - DESCRIPTION
The modular clutch assembly (Fig. 43) is serviced only as an assembly.



PL vehicles with a 1.6L engine uses a conventional style clutch with individually replaceable components. The clutch is located between the engine and manual transaxle in the transaxle bellhousing. The clutch system consists of the following components:
- Flywheel
- Clutch Disc
- Pressure Plate

DESCRIPTION - HYDRAULIC










The clutch hydraulic system (Fig. 2) (Fig. 3) consists of a clutch master cylinder assembly, and a clutch slave cylinder assembly, which may or may not incorporate an integral damper.


DESCRIPTION - FLUID

CAUTION: Never use any type of petroleum-based fluid (engine oil, transmission oil, power steering fluid, etc.) in the clutch hydraulic system. Use of such fluids will result in master/slave cylinder seal damage, and cause a failure of the hydraulic clutch release system.

NOTE: The clutch hydraulic system and replacement components are pre-filled, and under normal operating conditions, additional fluid is not required for the life of the vehicle.

The fluid required for use in the clutch hydraulic system is brake fluid conforming to DOT 3 specifications and J1703 standards. No other type of fluid is recommended or approved for use in the clutch hydraulic system. Use only Mopar brake fluid or equivalent from a tightly sealed container.







OPERATION - MECHANICAL
The clutch assembly is designed to transmit power from the engine to the manual transaxle. This is accomplished by the friction and clamping force generated when the spring loaded pressure plate locks the clutch disc to the flywheel (Fig. 4). The clutch disc, which is splined to the transaxle input shaft, transmits power until the center of the diaphragm spring is depressed, and the clamp force is removed from the disc.

OPERATION - HYDRAULIC
The clutch hydraulic system is responsible for engaging and disengaging the clutch. Depressing the clutch pedal develops fluid pressure in the clutch master cylinder. This pressure is transmitted to the slave cylinder through a connecting line. In turn, the slave cylinder operates the clutch release lever (Fig. 2) (Fig. 3)

The slave cylinder spring causes the release lever to hold the release bearing in constant contact with the diaphragm spring (release bearing preload). During a clutch pedal actuation, the hydraulic fluid pressure applies additional force to the release lever. As additional force is applied, the bearing presses the diaphragm spring fingers inward on the fulcrums. This action moves the pressure plate rearward, relieving clamp force on the disc.




CLUTCH INTERLOCK/UPSTOP SWITCH
Clutch Switch










DESCRIPTION - LHD
The LHD clutch interlock/upstop switch is an assembly consisting of two switches: an engine starter inhibit switch (interlock) and a clutch pedal upstop switch (Fig. 13). The switch assembly is located in the clutch/brake pedal bracket assembly (Fig. 14), each switch being fastened by four plastic wing tabs.








DESCRIPTION - RHD
The RHD clutch interlock/upstop switch (Fig. 15) consists of a single, multi-function switch that is activated by hydraulic clutch master cylinder push rod travel.

OPERATION - CLUTCH INTERLOCK SWITCH
The clutch interlock switch prevents engine starter operation and inadvertent vehicle movement with the clutch pedal in the up position (not depressed), or under normal conditions with the clutch engaged and the transaxle in gear.

WARNING: WHEN THERE IS A LOSS OF CLUTCH SYSTEM HYDRAULIC FLUID, OR THE CLUTCH MASTER CYLINDER PUSHROD IS DISCONNECTED FROM THE PEDAL LEVER, THE ENGINE MAY START WITH THE CLUTCH ENGAGED, CAUSING UNDESIRABLE VEHICLE MOVEMENT IF THE TRANSAXLE IS IN ANY GEAR.

The switch is open while the clutch pedal is at rest or in the up position. When the clutch pedal is fully depressed on LHD models, the clutch pedal lever closes the switch, completing the signal circuit from the PCM and closing the ground path, allowing engine starter operation. When the clutch pedal is fully depressed on RHD models, the master cylinder push rod closes the switch, completing the signal circuit from the PCM and closing the ground path, allowing engine starter operation. The interlock switch is not adjustable.

OPERATION - CLUTCH PEDAL UPSTOP SWITCH
With the clutch pedal at rest, the clutch pedal upstop switch is closed, allowing speed control operation. When the clutch pedal is depressed, the upstop switch opens and signals the PCM to cancel speed control operation, and enter a modified engine calibration schedule to improve driveability during gear-to-gear shifts. The upstop switch is not adjustable.