Clutch: Service and Repair
21 21 500 - Removing and installing or replacing clutch (SAC 228)
Special tools required:
Necessary preliminary tasks:
- Remove transmission 23 00 017 Removing and Installing Transmission (GS6-17BG).
Installation:
Screws must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Identification SAC clutch (Self-Adjusting Clutch):
- 3 openings each with a pressure piece (1) of adjustment ring and a pressure spring (2)
Note:
Illustration shows new position of pressure pieces.
Block flywheel with special tool 11 9 260.
Unfasten bolts and remove SAC clutch from flywheel.
Important!
Do not use a special tool to detach SAC clutch from flywheel.
Remove clutch plate (1) from flywheel.
Clean flywheel, check for wear and damage.
Replace damaged flywheel. Service and Repair
Check grooved ball bearing in crankshaft for ease of movement and tightness and if necessary replace grooved ball bearing.
Important!
Always replace clutch plates fouled e.g. by oil, cleaning agent.
Check clutch plate for damage and friction rust in hub profile and replace if necessary.
Check clutch disk for wear:
Measure lining protrusion at lining rivets at closing head (A) in each case.
Note:
Rivet connection
a) - Closing head
b) - Swage head
Replace clutch plate if lining protrusion at closing head (A) is less than 1 mm.
Push clutch disk onto the cleaned transmission input shaft and check for easy movability.
Important!
Do not clean SAC clutch with high-pressure cleaner or washing machine as this may impair function of adjustment unit.
Clean friction surface only.
Check SAC clutch for wear and damage and replace if necessary.
Reinstalling removed SAC clutch and clutch plate:
Installation:
N52
Screws must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Set SAC clutch (1) down on a clean surface.
Install special tool 21 2 180 in SAC clutch (1).
Note:
Locking hooks (1) of special tool 21 2 180 must engage in openings in SAC clutch.
Press special tool 21 2 180 together at handles (1) as far as it will go and grip firmly.
At same time tighten down knurled screws (2).
Adjustment ring of SAC clutch is now secured in its original position (wear position).
Important!
Do not reset adjustment ring to new position.
Note:
Insert special tool 21 2 170 only in area of bores for dowel pins.
Fit special tool 21 2 170 and tighten down at knurled screw (1).
Screw in spindle (1) until diaphragm spring (2) is tensioned up to stop.
Important!
Handle clutch disk carefully, do not touch surfaces of friction pads.
Install clutch plate in correct position.
Note designation for "engine side" / "transmission side".
Installation:
N52
Screws must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Centre clutch plate (1) with special tool.
Fit SAC clutch (1) on flywheel.
Pay attention to dowel pins (2).
SAC clutch (1) must be secured by way of dowel pins (2).
Insert screws and tighten down.
Tightening torque: 21 21 1AZ [1][2][3]Clutch Disc, M/T.
Release spindle (1) until tension is completely removed from diaphragm spring (2).
Release knurled screw (1) and remove special tool 21 2 170 from SAC clutch.
Release knurled screws (2) and remove special tool 21 2 180 from SAC clutch.
Withdraw special tool from clutch plate with aid of accompanying screw (1).
Installing removed SAC clutch with new clutch plate:
Installation:
N52
Screws must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Important!
Before installing an SAC clutch which has been in service with a new clutch plate: always reset adjustment ring in new position.
Set SAC clutch down on a clean surface.
Install special tool 21 2 180 in SAC clutch (1).
Note:
Locking hooks (1) of special tool 21 2 180 must engage in openings in SAC clutch.
Note:
Insert special tool 21 2 170 only in area of bores for dowel pins.
Fit special tool 21 2 170 and tighten down at knurled screw (1).
Screw in spindle (1) until adjustment ring of SAC clutch (2) can be turned with special tool 21 2 180 at handles (3).
Press special tool 21 2 180 together at handles (3) as far as it will go and grip firmly.
At same time tighten down knurled screws (2).
Adjustment ring of SAC clutch is now secured in new position.
Screw in spindle (1) until diaphragm spring (2) is tensioned up to stop.
Important!
Handle clutch plate with care, do not touch surfaces of friction linings.
Install clutch plate in correct position.
Pay attention to text "engine end" / "transmission side".
Installation:
N52
Screws must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Centre clutch plate (1) with special tool.
Fit SAC clutch (1) on flywheel.
Pay attention to dowel pins (2).
SAC clutch (1) must be secured by way of dowel pins (2).
Install retaining screws of SAC clutch and tighten down.
Tightening torque: 21 21 1AZ [1][2][3]Clutch Disc, M/T.
Release spindle (1) until tension is completely removed from diaphragm spring (2).
Release knurled screw (1) and remove special tool 21 2 170 from SAC clutch.
Release knurled screws (2) and remove special tool 21 2 180 from SAC clutch.
Withdraw special tool from clutch plate with aid of accompanying screw (1).
Installing new SAC clutch:
Installation:
N52
Screws must be replaced.
Jointing torque and angle of rotation must be observed without fail.
Important!
Handle clutch disk carefully, do not touch surfaces of friction pads.
Install clutch plate (1) in correct position.
Note designation for "engine side" / "transmission side".
Centre clutch plate (1) with special tool.
Push SAC clutch onto dowel pins (1) located in flywheel and screw down.
Tightening torque: 21 21 1AZ [1][2][3]Clutch Disc, M/T.
Important!
Locking piece (1) may only be removed with SAC
screw-mounted clutch!
Carefully unscrew locking piece (1) clockwise or counterclockwise with a hexagon socket wrench 14 A/F (2).
Note:
A slight snapping of the plate spring while unscrewing is possible.
Withdraw special tool from clutch plate with aid of accompanying screw (1).