Clutch Driving Members; Clutch Driven Members; Clutch Operating Members; Hydraulic Clutch Description - Chevrolet Corvette 2005 Owner's Manual

2005 Chevrolet Corvette Restoration Kit
The following are the principal components of the clutch system:
• The driving members; attached to the engine and turning with the engine.
• The driven member; attached to the driveline and transmission and turning with the driveline and
transmission.
• The operating members; including the spring, the clutch hydraulic system, and the clutch pedal
linkages, required to apply and release the pressure, which holds the driving and driven members
in contact with each other.
Clutch Driving Members
The clutch driving members consist of two, flat surfaced, iron plates, machined to a smooth finish. One of
these surfaces is the rear face of the engine flywheel and the other is a comparatively heavy flat ring, with
one side machined, known as the clutch pressure plate.
Clutch Driven Members
The driven member (clutch disc) has a splined hub that freely slides lengthwise along the splines of the
input shaft, which also drives the shaft through these same splines. Suitable friction facings are attached
to each side of the plate by rivets.
In order to make the clutch engagement as smooth as possible and eliminate chatter; the steel segments
driving the splined hub are slightly waved, which causes the contact pressure on the facings to rise
gradually as the waved springs flatten out.
Clutch Operating Members
The driving member and the driven member are held in contact by spring pressure. This pressure is
exerted by a one-piece conical or diaphragm spring.
A diaphragm spring is a conical piece of spring steel that has been specially stamped to give it greater
flexibility. The diaphragm is positioned between the cover and the pressure plate so that the diaphragm
spring is nearly flat when the clutch is in the engaged position. The action of this type of spring is similar
to that of an ordinary oil can.
The pressure of the inner rim of the spring on the pressure plate decreases as the flat position is passed.
The inner rim of the diaphragm bears on the pressure plate and is pivoted on a ring on the outer edge of
the pressure plate. The application of a pulling load on the inner section of the pressure plate will cause
the inner rim to move away from the flywheel and allow the pressure plate to move away from the clutch
disc, thereby releasing or disengaging the clutch. When the pressure is released from the inner section,
the OIL CAN action of the diaphragm causes the inner section to move in, and the movement of the inner
rim forces the pressure plate against the clutch disc, thus engaging the clutch.
The clutch release bearing is moved by the actuator assembly to move the release levers which move the
pressure plate to the rear, thus separating the clutch disc from the flywheel when the clutch pedal is
depressed by the driver. A piston return spring in the actuator cylinder preloads the clutch linkage and
assures a small load on the release bearing with the actuator assembly at all times. As the clutch disc
wears, the diaphragm spring fingers move forward forcing the release bearing, actuator assembly, and
pushrod to move. This movement forces the actuator cylinder piston to move forward in its bore,
consuming hydraulic fluid from the master cylinder reservoir, thereby providing the SELF-ADJUSTING
feature of the hydraulic clutch linkage system.
Hydraulic Clutch Description
The clutch hydraulic system consists of a master cylinder and an actuator cylinder. When pressure is
applied to the clutch pedal (pedal depressed), the pushrod contacts the plunger and pushes it down the
bore of the master cylinder. In the first 0.8 mm (0.031 in) of movement, the recuperation seal closes the
port to the fluid reservoir tank, and as the plunger continues to move down the bore of the cylinder, the
fluid is forced through the outlet line to the actuator cylinder mounted to the driveline support assembly.
As fluid is pushed down the pipe from the master cylinder, this in turn forces the piston in the actuator
cylinder outward. As the actuator cylinder piston moves forward, it forces the release bearing to
disengage the clutch pressure plate from the clutch disc. On the return stroke (pedal released), the
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