Clutch: Description and Operation

The principal parts of the clutch system are the driving members, the driven members, and the operating members. The clutch housing on some models are part of the manual transmission assembly.

DRIVING MEMBERS

The driving members consist of two flat surfaces machined to a smooth finish. One of these is the rear face of the engine flywheel, and the other is the front face of the clutch cover assembly.

DRIVEN MEMBERS

The driven member is the clutch disc with a splined hub that is free to slide lengthwise along the splines of the input shaft, and drives the input shaft through the same splines.

The driving and driven members are held in contact by spring pressure. This pressure is exerted by a diaphragm spring in the clutch cover assembly.

OPERATING MEMBERS

The clutch release system consists of a combined clutch master cylinder, reservoir, switch, and actuator cylinder connected to hydraulic tubing.

When the clutch pedal is depressed, the clutch master cylinder push rod is forced into the clutch master cylinder causing the clutch master cylinder to become pressurized. Hydraulic fluid is then forced down the hydraulic tubing from the clutch master cylinder to the concentric slave cylinder. When the hydraulic fluid is pushed into the slave cylinder, the slave cylinder engages by pushing the release bearing into the diaphragm spring and releasing the clutch.

The clutch master cylinder is positioned through the cowl panel. The hydraulic tubing is routed from the clutch master cylinder to the concentric slave cylinder via a quick connect coupling. The concentric slave cylinder is located inside the transmission on the transmission input bearing retainer.

Replacement of the hydraulic control system is made easier because the hydraulic tubing connecting the slave cylinder to the master cylinder can be removed from the internalized slave cylinder by engaging the quick connect coupling mounted through the transmission housing. This allows replacement of the hydraulic control system without having to gain access to the transmission internal components.

The hydraulic clutch system provides automatic clutch adjustments, no adjustment of clutch linkage or pedal position is required. As the clutch disc wears, the fluid level in the master cylinder reservoir will rise to accommodate for the extra fluid not required in the hydraulic system. A new system will have a completely filled reservoir, with the hydraulic fluid level at the top of the reservoir.

A two function electrical switch, located on the push rod, is used as a clutch interlock to ensure that the engine does not start unless the clutch pedal is engaged (positioned to the floor). A second function of the switch is to cut off the cruise control system (if the vehicle is so equipped) when the clutch pedal is engaged.

HYDRAULIC CLUTCH FLUID

When adding fluid to or refilling the system after service operations use GM Delco Supreme No. II(R) Brake Fluid P/N 1052535 or equivalent fluid that meets DOT 3 specifications.

CAUTION: Do not use mineral or paraffin base oil in the clutch hydraulic system. These fluids will damage the rubber parts in the cylinders.