Crankshaft: Service and Repair
11 21 500 - Replacing crankshaft (N51)
Special tools required:
- 00 2 510 00 2 510 Dial Gauge with Feeler
- 00 9 120 00 9 120 Torque Angle Measuring Dial
- 11 4 370 11 4 370 Device
- 11 4 440 11 4 440 Engine Support Plate
- 11 9 360 11 9 360 Mandrel
Important!
Aluminium-magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released.
Aluminium screws/bolts are permitted with and without
colour coding (blue).
For reliable identification:
Aluminium screws/bolts are not magnetic.
Jointing torque and angle of rotation must be observed without fail (risk of damage).
Necessary preliminary tasks:
- Remove engine Removing and Installing Engine.
- Mount engine on assembly stand 11 00 ... Mounting Engine on Assembly Stand.
- Remove vibration damper Service and Repair.
- Removing oil sump Service and Repair.
- Remove oil pump 11 41 000 Removing and Installing/Replacing Oil Pump.
- Remove oil pump/vacuum pump chain module 11 41 010 Removing and Installing/Replacing Chain Module For Oil Pump/Vacuum Pump.
- Remove timing chain module .
- Remove cylinder head Removal and Replacement.
- Remove flywheel.
- Remove all pistons Service and Repair.
Release screws (1).
Tightening torque: 11 13 5AZ [1][2]11 13 Oil Sump.
Installation Note:
Replace aluminium screws.
Remove oil deflector (2).
Release screws (1).
Tightening torque: 11 11 2AZ. Mechanical Specifications
Unfasten screws (2).
Tightening torque: 11 11 3AZ. Mechanical Specifications
Installation Note:
Replace aluminium screws.
Release screws (1).
Tightening torque: 11 11 2AZ. Mechanical Specifications
Unfasten screws (2).
Tightening torque: 11 11 4AZ. Mechanical Specifications
Installation Note:
Replace aluminium screws.
Release steel screws (1 to 14) from outside inwards.
Tightening torque: 11 11 1AZ. Mechanical Specifications
Release screws (1).
Tightening torque 11 11 3AZ. Mechanical Specifications
Installation Note:
Replace aluminium screws.
Remove crankcase lower section in upward direction.
Remove crankshaft (1) in direction of arrow.
Important!
Remove crankshaft with aid of a second person.
Weight of crankshaft approx. 25 kg.
Remove main bearing shells(2 and 3), replace if necessary.
Check adapter sleeves (1) for damage and secure seating; replace if necessary.
Insert all crankshaft main bearing.
Installation Note:
Lubricate all bearing points with engine oil.
Note:
Illustrations show N46.
Insert crankshaft (1).
Important!
Remove crankshaft with aid of a second person.
Weight of crankshaft approx. 25 kg.
Tighten steel screws (1 to 14) from inside outwards.
Tightening torque: 11 11 1AZ. Service and Repair
Tighten screws (2) from inside outwards.
Tightening torque: 11 11 4AZ. Mechanical Specifications
Tighten screws (1).
Tightening torque: 11 11 2AZ. Mechanical Specifications
Installation Note:
Replace aluminium screws.
Tighten aluminium screws exclusively with special tool 00 9 120.
Important!
In the case of aluminium screws, jointing torque and angle of rotation must be observed without fail.
Set up stand with magnetic base on special tool 11 4 440.
Set up special tool 00 2 510 on stand.
Position special tool 00 2 510 on crankshaft.
Move crankshaft in direction of arrow.
Determine bearing play.
Drive in both nozzles (1) with special tool 11 9 360 on left and right into crankcase.
Installation Note:
Always replace nozzles (1).
Replace radial shaft seal at front. Service and Repair
Replace radial shaft seal at rear. Service and Repair
Installation Note:
Use primer 1.3 and liquid gasket 1.4 Procedures.
Prepare liquid gasket (1) in special tool 11 4 370.
Screw on nozzle for injecting liquid gasket.
Slowly insert liquid gasket (1) with special tool 11 4 370 in direction of arrow.
Stop (seal off) escaping liquid gasket with primer 1.3.
(Picture shows N40).
Assemble engine.