Warning: When the clutch is in operation, dust containing asbestos, which is harmful to health, is generated, so when cleaning the clutch, do not use compressed air or inhale the dust. Clean the clutch parts from dust using brake fluid or methyl alcohol, and then wipe dry.
Fig. 8–8. Flywheel and clutch: 1 – dual mass flywheel; 2 – bolt, 60 Nm + turn further by 180°; 3 – driven clutch disc; 4 – clutch pressure plate; 5 – bolt, 22 Nm; 6 – needle bearing
When installing, it is necessary to use new bolts 2 (Fig. 8–8).
Lubricate the splines of the driven disk with a thin layer of G000100 grease. The layer of grease must be thin and uniform, otherwise, when the clutch is operating, excess grease will be thrown onto the working surfaces of the clutch, which may disrupt its operation.
Tighten bolts 5 evenly diagonally.
Removal
Remove the gearbox.
Mark the position of the clutch assembly in relation to the flywheel with a marker or paint.
Fig. 8–9. Using tools when removing and installing the driven clutch disc: 3067 – tool for fixing the flywheel from turning; 3176 – Clutch Disc Centering Mandrel
Using a special tool VW–3067 or a screwdriver, lock the flywheel ring gear teeth to prevent it from turning (Fig. 8–9).
Gradually loosen the clutch assembly mounting bolts diagonally, turning each bolt a half turn until the spring force is released and the bolts can be removed by hand.
Remove the pressure plate, while supporting the driven plate so that it does not fall out.
Clean any dirt from the clutch release bearing, but do not use solvents.
Wipe the flywheel with gasoline.
Examination
Fig. 8–10. Locations for checking the pressure diaphragm spring for wear
Check the condition of the clutch pressure plate. The wear marks on the ends of the pressure spring should be no more than 0.3 mm (Fig. 8–10).
Fig. 8–11. Checking points for riveted and spring connections
Check the reliability of the spring connection between the pressure plate and the clutch housing. No scratches or missing or damaged rivets are allowed (Fig. 8–11).
Check the pressure plate for cracks, burns and surface wear.
Using a steel ruler and a feeler blade, check the non-flatness of the working surface of the pressure plate. The non-flatness of the pressure plate should not exceed 0.2 mm.
Check the condition of the flywheel friction surface for cracks, burns and surface wear.
Check the condition of the friction linings of the driven clutch disc and if there are traces of oil or mechanical damage, replace the driven disc.
Measure the thickness of the clutch driven disc linings. If their thickness is less than the permissible value or if the rivet heads are close to the working surface, replace them or the clutch driven disc.
Check the condition of the clutch release bearing, which should rotate easily, evenly and quietly and should have no play. The working surface of the bearing acting on the pressure spring should be smooth, without cracks, local corrosion or wear.
A faulty clutch release bearing can be identified without removing it from the vehicle by pressing the clutch pedal while the engine is running. If noise occurs when the clutch pedal is pressed, the clutch release bearing is faulty and must be replaced.
Installation
When installing a new driven disc or pressure plate, remove the anti-corrosion protection from them.
When installing the driven disk, make sure that no oil gets on its friction linings, even in small quantities. Therefore, before installing, wipe the mating surface of the flywheel and the surface of the pressure plate with a clean rag, install the driven disk with clean hands.
Lubricate the splines in the driven disk hub with a thin layer of special grease based on molybdenum disulfide.
Install the driven disk on the flywheel so that the protruding part of the disk hub is directed outward, towards the gearbox.
Install the clutch assembly, aligning the holes in the clutch housing with the flywheel guide pins. When reinstalling a previously removed clutch pressure plate, check that the marks made before removal are aligned.
Tighten the clutch housing mounting bolts so that the driven clutch disc is pressed down, but at the same time can still move sideways.
Using a special drift or an old gearbox input shaft, center the clutch disc relative to the flywheel.
The driven clutch disc can be centered using a special mandrel relative to the housing with the pressure plate assembly.
After centering the driven disk, gradually tighten the clutch housing mounting bolts diagonally to a torque of 25 N·m.
Remove the mandrel from the driven disk.
Lubricate the splined portion of the gearbox input shaft and the clutch release bearing guide sleeve with a thin layer of special molybdenum disulfide-based grease.
Install the gearbox.
(The original article is posted on the resource «AudiManual.ru»)