Clutch: Service and Repair

Removing and Installing/Replacing Clutch (SAC)
(Transmission removed)

SAC clutch:
(Self Adjusting Clutch)

Identifying feature:
3 recesses, each with one pressure piece (1) on the adjustment ring and one compression spring (2).

Note: Figure shows new position of pressure piece.

Arrest flywheel with special tool 11 2 070.

Mount special tool 21 2 150 on SAC clutch.

Pretension diaphragm spring (1) of SAC clutch up to stop with special tool 21 2 150.

Unfasten bolts and remove SAC clutch from flywheel.

Remove clutch disk (1) from flywheel. Clean flywheel and check for wear and damage. Replace flywheel if necessary.

Check grooved ball bearing in crankshaft for ease of movement and tightness and if necessary replace.

Check clutch disk for damage and friction rust in hub profile and replace if necessary.

Caution! Clutch disks dirtied by foreign materials (oil, cleaning agent etc.) must always be replaced.

Check clutch disk for wear:
Measure lining protrusion at each lining rivet on closing head (A).

Note: Rivet connection
A) Closing head
B) Swage head

The clutch disk must be replaced if the lining protrusion at the closing head (A) is less than 1 mm.

Push clutch disk onto cleaned transmission input shaft and check for easy movability.

Caution!
- Do not clean the SAC clutch with a high-pressure cleaner or parts washing machine, as otherwise the function of the slack-control device is no longer ensured.
- Only the friction face may be cleaned.
- Check SAC clutch for wear and damage and replace if necessary.

Reinstalling removed SAC clutch:

Note: Before installing a used SAC clutch, the adjustment ring must always be reset to the new position!

Mount SAC clutch on flywheel and secure with two bolts (without clutch disk).

Loosen special tool 21 2 150 until adjustment ring on thrust pieces (1) can be moved.

Turn back adjustment ring on one of the thrust pieces (1) to the stop and secure with special tool 21 2 154.

Tighten special tool 21 2 150 up to stop.

Push pressure plate (1) away from flywheel with a screwdriver (2) until the sensor plate spring in the SAC clutch audibly snaps over.

Remove SAC coupling from flywheel.

Caution!
- Handle clutch disk carefully, do not touch surfaces of friction pads.
- Install clutch disk (1) in proper position.
- Note designation for "engine side"/"transmission side"!
- 5-speed transmission:
Center clutch disk with special tool 21 2 142.
- 6-speed transmission:
Center clutch disk with special tool 21 2 141.

Push SAC clutch onto dowel pins (1) in flywheel and screw down.

Tightening torque, refer to Specifications.

First loosen special tool 21 2 150 and remove, then remove special tool 21 2 154.

Pull special tool 21 2 141 or 21 2 142 out of the clutch disk with the bolt (1) provided.

Installing new SAC clutch:

Push SAC clutch onto dowel pins (1) in flywheel and screw down.

Tightening torque, refer to Specifications.

Caution! The locking piece (1) may only be removed with the SAC clutch screwed down!

Carefully screw out locking piece (1) clockwise with a 14 mm Allen key (2).

Note: A slight snapping of the plate spring while unscrewing is possible.

Pull special tool 21 2 141 or 21 2 142 out of clutch disk with the bolt (1) provided.