Clutch Disc: Service and Repair
Pressure plate/clutch driven plate, replacing
Special tools:
998 9742 Conversion kit 998 9742 Conversion Kit
999 5112 GEAR SECTOR 999 5112 Gear Sector
999 5662 Compression tool 999 5662 Compression Tool
999 5663 Centering tool 999 5663 Centering Tool
999 5675 Socket 999 5675 Socket
999 7068 Counterhold 999 7068 Counterhold
Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information is always correct.
Removal
Preparatory work
Note! To remove the transmission, Transmission, Removing.
Note! If the clutch must be replaced there is no need to use the counterhold for the automatic adjustment and the compression tool. The clutch screws can then be removed.
Caution! Under no circumstances may a clutch which has been removed in the way described above be reused.
When removing and installing new or existing clutches, the counterhold for automatic adjustment and the compression tool must be used. This procedure is described in the following procedure.
Blocking the flywheel
Use gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector.
Marking the mounting points for the compression tool hooks
The compression tool hooks can only be located in a specific position (opposite the rivets for the reinforcement springs for the clutch). Mark these positions using a marker pen. When the counterhold is installed it is difficult to locate the positions exactly.
Installing the counterhold
The three pins on the counterhold lock the automatic adjustment.
Position the counterhold 999 7068 Counterhold 999 7068 Counterhold as shown in the illustration.
Ensure that all the three pins (see the illustration) go down into the correct side in front of the hooks for the automatic adjuster.
Press the counterhold ring against the pressure plate. Pull out the counterhold springs. Secure the three hooks in the holes in the clutch as illustrated.
Installing compression tool
Install the compression tool 999 5662 Compression tool 999 5662 Compression Tool , together with a rebuild kit 998 9742 Conversion kit 998 9742 Conversion Kit , on the clutch.
Align the hooks on the tool with the markings made previously. Ensure that the hooks grip the clutch housing properly.
Center the compression tool and tighten the screw to light contact against the diaphragm spring. At the same time, check that the hooks on the tool are in position.
Note the position of the handle with slots. Then screw in by not more than two turns.
Remove the clutch and clutch driven plate. The tools can remain in place on the clutch if it is to be reused.
Note! Take care not to trap any fingers when removing the tool.
Checking the clutch
Wipe the clutch. Use a dry cloth.
Check carefully for damage through over-heating, cracks, scoring or other damage to the friction surface.
Check that spring is not damaged or broken.
Checking the pressure plate for out-of-true
Wipe the pressure plate friction area clean.
Check any out-of-true carefully. Use a ruler and a feeler gauge. Out-of-true is permitted in one direction only.
Out-of-true must not exceed 0.2 mm. If out-of-true is greater, replace the clutch.
The clutch must be replaced as a complete unit.
Checking the clutch driven plate
Wipe off the clutch driven plate. Use a dry cloth. The cloth must be free of oil and contaminants.
Check the clutch carefully for signs of wear, damage through overheating, cracking or other damage.
Note! The clutch driven plate must always be replaced if there are no radial ripples remaining on the friction coating. The clutch driven plate must also be changed if there is oil or grease on it.
Checking the flywheel
Check that there are no cracks or large scratches on the flywheel.
To replace the flywheel, see Flywheel, B5254T2, M56 Service and Repair.
Check radial run-out.
Installation
Installing the centering tool for the clutch driven plate
Use centering drift 999 5663 Centering tool 999 5663 Centering Tool , alternatively together with 999 5675 Socket 999 5675 Socket. The drift is modified with conversion kit 998 9742 Conversion kit 998 9742 Conversion Kit.
Remove the cone from the centering tool.
Install the centering tool in the flywheel center as far in as possible.
Use a wrench as a counterhold for the outer section of the centering tool. Tighten the nut so that the expander locks the centering tool in the crankshaft.
Ensure that the centering drift is secure in the crankshaft.
Installing the clutch driven plate
Caution! Turn the side of the clutch driven plate hub marked "Transmission side" outward. If the marking on a previously used clutch driven plate is erased, the illustration clearly depicts how the clutch driven plate must be installed.
Install the cone on the centering tool. Tighten the cone (by hand). Secure the clutch driven plate.
Note! Tightening tools must not be used on the cone or damage may be caused to the clutch driven plate.
Installing the compression tool on a removed clutch
Note! A clutch must never be installed without using a compression tool.
Mark where the compression tool hooks should be seated. See Blocking the flywheel.
Install the counterhold for automatic adjuster for the clutch. See Installing the counterhold.
Install the compression tool on the clutch. See Installing compression tool.
Tighten the compression tool until the diaphragm spring has pressed the clutch pressure plate to the free position. A loud click can be heard when the clutch pressure plate "snaps out".
The clutch is now ready for installation with the compression tool and counterhold in position.
Installing the clutch
Install the clutch. Locate the clutch on the guide pins on the flywheel.
Check that the clutch is in contact with the flywheel all around its circumference.
Install and tighten the 6 x M8 screws crosswise.
Removing tools
Slacken off and remove the screw on the compression tool.
Note! Keep fingers away from the three clutch rivets when removing the compression tool. There is a risk of compression damage.
Remove the hooks. Remove the counterhold.
Remove the cone from the centering tool.
Slacken off the nut. Tap the centering tool lightly so that the expander releases. Use a rubber mallet. Use a rubber mallet so that the threads are not damaged. Remove the centering tool.
Remove the flywheel gear sector. Check the flywheel. Service and Repair.
To install the transmission, Transmission, Installation.