Removal
Remove the gearbox.
Loosen the mounting bolts (1) (6 pcs.) of the clutch pressure plate one by one by 1-1.5 turns at a time until the pressure plate is released. To prevent the flywheel from turning when unscrewing the bolts, secure it with a rod or screwdriver.
Caution: If you unscrew the bolts immediately, you may damage the diaphragm spring and the guide pins (2) between the pressure plate and the flywheel.
Finally, completely unscrew the bolts.
Remove the pressure and driven clutch discs.
Attention: The discs must not fall when removed, otherwise jerking and difficulty engaging the clutch may occur after installation.
Clean the flywheel with a rag soaked in gasoline.
Examination
Check the clutch pressure plate for signs of burning and deep scratches and replace it if necessary.
Check the diaphragm spring for damage (arrows).
Check the spring connections between the pressure plate and the cover for cracks, the fastening of the rivets and the tightness of the fit. Replace the disk with damaged or loose rivets.
Check the working surface of the pressure plate for scratches, traces of burning and wear. Disks that have concavities up to 0.3 mm deep can be used further. Checking is done with a ruler and flat feeler gauges.
Check the flywheel for signs of overheating and pitting.
Treat the clutch pressure plate and flywheel with the finest sandpaper.
An oily or damaged driven disk must be replaced.
Measure the thickness of the working lining of the driven clutch disc using a caliper. The distance to the rivet heads should be at least 0.3 mm. Otherwise, the driven disc must be replaced. The same applies to damaged linings.
The driven clutch disc can be checked for runout in the workshop. Lateral runout should not exceed 0.25 mm.
Note: This check is only necessary if an old driven disc is to be installed and there were previous problems with the clutch operation.
Check the release bearing in the gearbox housing. There should be no visible signs of deformation. Turn the bearing by hand. It should not stick. If the bearing makes noise when disengaging the clutch, it also needs to be replaced.
Installation
Attention: Before installing a new clutch, you must wash off the protective varnish with solvent from the working surface of the pressure plate, and also wipe the flywheel.
Check the three centering pins on the flywheel for tightness.
Roughly center the driven disk in the middle of the pressure plate. However, it is better to do this with a special rod or an old primary shaft of the gearbox.
In specialized workshops, a special device is used. If the driven disk is not centered, it will be impossible to insert the primary shaft of the gearbox later.
Install the pressure plate with the driven plate centered onto the corresponding flywheel mounting pins.
Insert the clutch pressure plate mounting bolts and screw them in by hand, then tighten them crosswise by 1-1.5 turns until the pressure plate is tightened.
Caution: Make sure that the pressure plate is pulled evenly and without distortion toward the flywheel when tightening the bolts. The tightening torque of the bolts is 30 Nm.
Pull out the centering rod.
If used, remove the flywheel locking device.
Clean the gearbox input shaft splines and lightly lubricate them with molybdenum-based grease. Do not use too much grease or it will be squeezed out onto the clutch working surfaces, causing the clutch to slip.
Install the gearbox.