Flywheel: Service and Repair
Flywheel, replacement
Replacing the flywheel
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.
Replacing the flywheel
Petrol engines
To replace the flywheel, see Replacing the flywheel (Petrol).
Diesel engines
To replace the flywheel, see Replacing the flywheel (Diesel).
Replacing the flywheel (Petrol)
Special tools:
999 5112 GEAR SECTOR 999 5112 Gear Sector
999 5678 Special screw 999 5678 Special Screw
Removal
Preparatory work
To remove the gearbox, see Removing the transmission Transmission, Removal.
To remove the clutch, see Checking and/or replacing the clutch and clutch driven plate, M56 Service and Repair.
Note! The illustrations in the method show a dual mass flywheel, but the method is the same for cars with a solid flywheel
Removing the flywheel
Remove the engine speed (RPM) sensor with bracket and put to one side.
Undo all screws to the flywheel. Remove all screws apart from one.
Remove the gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector.
Detach the flywheel from the crankshaft and remove the remaining screw.
Remove the flywheel.
Checking the crankshaft seal
Check the crankshaft seal for leakage.
To replace the crankshaft seal, see the car and model year in question.
Installation
Installing the flywheel
Note! Check that the contact surfaces on the crankshaft and the flywheel are totally clean.
Use tool 999 5678 Special screw 999 5678 Special Screw , which comprises 3 studs with nuts.
Install:
- 3 studs of the tool 999 5678 Special screw 999 5678 Special Screw with the division shown in the illustration
- the flywheel.
Note! Check that the stud on the crankshaft is opposite the hole in the flywheel.
Note! Only applies to engines with dual mass flywheel: There is a marking in the form of a shallow hole (see arrow). The marking shows the direction of the guide hole location on the flywheel.
Align the gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector to the flywheel.
Draw the flywheel in to the crankshaft with the nuts alternately. Use the 3 nuts from the tool 999 5678 Special screw 999 5678 Special Screw.
Caution! The flywheel must sit against the crankshaft face before the screws are applied. There is a risk that surplus lock paint on the screws enters between the contact surfaces.
Fit 7 new screws. Tighten crosswise to 45 Nm .
Remove the 3 nuts and studs.
Fit the remaining 3 new screws to the flywheel and tighten to 45 Nm . Following which, angle tighten all 10 screws crosswise 65°.
Fit the engine speed (RPM) sensor with bracket. Tighten to 10 Nm .
Finishing
For installing the clutch, see Checking and/or replacing the clutch and clutch driven plate, M56 Service and Repair.
To install the gearbox, see Transmission, installing Transmission, Installing.
Replacing the flywheel (Diesel)
Special tools:
999 5112 GEAR SECTOR 999 5112 Gear Sector
Removal
Preparatory work
Note! The illustrations in the method show a dual mass flywheel, but the method is the same for cars with a solid flywheel
Removing the flywheel
Undo all screws to the flywheel. Remove all screws apart from one.
Remove the gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector.
Detach the flywheel from the crankshaft and remove the remaining screw.
Remove the flywheel.
Checking the crankshaft seal
Check the crankshaft seal for leakage.
To replace the crankshaft seal, see the car and model year in question.
Installation
Installing the flywheel
Note! Check that the contact surfaces on the crankshaft and the flywheel are totally clean.
Fit the flywheel.
There are different distances between the screw holes which means that the flywheel only fits in one way.
Use new screws.
Fit the gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector
Fit the gear sector 999 5112 GEAR SECTOR 999 5112 Gear Sector.
Tighten the screws crosswise to 60 Nm . Following which, angle tighten all screws crosswise 90°.
Remove the counterhold 999 5112 GEAR SECTOR 999 5112 Gear Sector