Clutch Situation: C5 Twin-Disc Clutch Install

Before John installs the new release (also referred to as the slave)cylinder and release bearing to the propeller shaft in the drivelinesupport assembly, he takes a moment to enhance the performance of thehydraulic clutch. He uses a small drift to remove the roll pin retainingthe hydraulic hose to the actuator cylinder.

The hydraulic actuator cylinder hose is produced with a narrowed openingthat restricts the flow of hydraulic fluid and thus slows the clutchoperation. The OE purpose for this restriction, as John explains it, isto minimize driveline shock to the rearend, but by slowing down theclutch, it adversely causes more wear to the clutch plates instead.

John very carefully drills out the restricted hose opening in order tomake full use of the new clutch.

With the plug removed, the hydraulic clutch can now operate at its fullpotential. John reattaches the hose to the new release cylinder, andtaps the roll pin retainer back into place with the small drift.

On the forward end of the driveline support assembly, John unbolts andslides off the old release cylinder assembly, wipes off the exposedpropeller shaft end with a clean, dry cloth to remove contaminants, thenbolts the new release cylinder in place.

We're now ready to lift the driveline back up into the car.

As John puts it, this is now the time for lots of expletives, as heworks to line up the propeller shaft spline with the clutch plates andpilot bearing. It's rather awkward getting the trans/diff unit and thetorque tube in the correct position, at the correct angle of incline,and get the splines to mesh.

Nonetheless, John works through the 3D puzzle in about 10 minutes. Oncehe gets the driveline support assembly positioned where he needs it,John rotates the flywheel by minute degrees until the propeller shaftslips through the clutch plates into the pilot bearing, and the releasecylinder fits flush to the clutch diaphragm spring.

After he bolts the torque tube securely to the bell housing, Johnreaches up along the left inner frame-rail, just above where the oilfilter is located, and connects the clutch actuator cylinder hose to themaster cylinder hose. He uses a pair of channel-lock pliers to push thequick release fittings on the hoses together.

John now lowers the C5 back down temporarily to clean out the clutchfluid reservoir and refill it. To avoid contaminants and impurities, hesoaks up all remaining old fluid with a rag, and wipes the reservoirclean before filling it with fresh Motul RBF 600 hydraulic fluid.

Then, with the car in the air again and Tito in it to operate the clutchpedal, John bleeds the air out of the clutch. While Tito presses andholds the clutch pedal, John loosens the bleeder screw on the clutchactuator cylinder to bleed the line. John tightens the bleeder, Titoreleases the pedal, and they repeat the process until all the air isevacuated, making sure the reservoir doesn't run dry.

The installation is complete. John replaces the flywheel inspectioncover, reattaches the driveline tunnel closeout panel, reassembles theexhaust and rear suspension, and away we go. The new clutch requires 750break-in miles without abuse, but then we'll finally see what this babycan do!