Inspect the clutch spin down time as follows:

1. Block the vehicle wheels, and apply the parking brake.
2. Shift the transmission into neutral.
3. Start the engine, and run at idle speed.
4. Engage the clutch.
5. Disengage the clutch, and wait 9 seconds.
6. Shift the transmission into reverse.
7. If you hear a grinding noise, refer to Release Bearing Noisy with Clutch Engaged .

The clutch driving members are 2 flat surfaces, machined to a smooth finish:

The driven member is the clutch driven plate. The clutch driven plate has a splined hub. The splined hub slides lengthwise along the splines of the input shaft. The splined hub drives the input shaft through these same splines. The driving and driven members are held together with a spring pressure. This pressure is exerted by a diaphragm spring in the clutch pressure plate.

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

When refilling the system, or adding fluid after service, use GM Delco Supreme No. 2 Brake Fluid, or equivalent, that meets DOT 3 specifications.

The clutch system consists of the following components:

With the depression of the clutch pedal, the clutch master cylinder becomes pressurized from the force of the push rod into the master cylinder. This forces hydraulic fluid into the tubing from the master cylinder to the concentric slave cylinder. The concentric slave cylinder then engages by pushing the release bearing into the diaphragm spring and releases the clutch. A hole in the cowl panel accommodates the master cylinder. A quick connect coupling helps route the hydraulic tubing. The concentric slave cylinder is inside the transmission and on the input bearing retainer. The hydraulic control system can be replaced without having to gain access to the clutch system internal components by engaging the quick connect coupling, mounted through the transmission housing. No adjustments to the clutch system are necessary. As the clutch wears, the fluid level in the master cylinder reservoir changes to compensate for clear wear. A new system will have fluid in the reservoir. An electrical switch on the push rod has 2 functions. One function is a clutch interlock, ensuring the engine does not start unless the clutch pedal is engaged, positioned to the floor. The second function is to cut off the cruise-control system, if equipped, when the clutch pedal is engaged.