Clutch: Description and Operation

SAC, C70/S7O/V70, Self-Adjusting Clutch
As regards function the pressure plate and clutch driven plate are a single unit.
The pressure plate is of the diaphragm spring type. However, the pressure plate contains a plastic adjustment ring. When there is wear the adjustment ring automatically moves a little so that the operating clutch travel remains constant.
Two new tools are required for work on the clutch. One to compress the pressure plate before removing it, and one to fix the automatic adjustment before installing it.
The clutch driven plate does not have torsion dampers and friction surfaces. Instead these functions are integrated into the dual mass flywheel.

Function
When the clutch driven plate coating wears down, the normal working position (travel) of the pressure plate changes and clutch disengagement pressure increases.
On the self-adjusting clutch an adjuster ring responds to the wear of the clutch driven plate. When there is wear the adjustment ring automatically moves a little when the clutch is engaged adjusting bearing point of the diaphragm spring. This means that the operating travel of the pressure plate and therefore engagement pressure remain constant.

Variants
The following are available for the S/V70:
Engines: B 5254 T, B 5204 T3
Transmissions: M56/58/59





CSC. (C70/S70/V70), Concentric Slave Cylinder
The introduction of the CSC means that the slave cylinder is integrated with the throwout bearing.
The CSC is more powerful, has better throwout bearing centering, is more reliable and is easier to install.
The sleeve/throwout bearing and slave cylinder are integrated in the CSC via an adapter. The unit is secured to the transmission cover with two screws. There is no longer a problem with the lubrication of bearings and friction surfaces.
The hydraulic lead from the master cylinder is connected to the CSC via an adapter. There is a bleed nipple on the adapter. The adapter can be accessed through the old opening for the throwout arm.

The CSC is used on the following models
The following are available for the S/V70:
Engines: All engines
Transmissions: M56/58/59