Crankshaft: Service and Repair

11 21 500 Replacing crankshaft (N18)






Special tools required:
- 00 9 120
- 11 4 471
- 11 4 472
- 11 6 251
- 11 6 252
- 23 1 240






Warning!
Rotating components (danger of injury!).
It is absolutely essential to follow the procedure described below and the instructions on handling the special tools.






Important!
Jointing torque and angle of rotation must be observed without fail (risk of damage).






Necessary preliminary work:
- Remove engine.
- Mount engine on assembly stand.
- Remove vibration damper.
- Removing oil sump.
- Remove oil pump.
- Remove timing chain.
- Remove cylinder head.
- Remove flywheel.






Release screws (1).
Tightening torque 11 13 3AZ.
Remove oil deflector (2).
Remove all pistons.






Important!
Risk of damage! on crankcase.

Drive out cover plates (1) with a cross-cut chisel (2).






Release screws (28 to 11).
Release screws (10 to 1).






Release crankcase lower section in direction of arrow with a regular screwdriver (2) and an open-end spanner (1) at press-off lug.






Remove both radial shaft seals (1).

Note:
Graphic shows N43.






Remove crankshaft (1).

Important!
Remove crankshaft with aid of a second person.
Weight of crankshaft approx. 19 kg.

Remove main bearing shells, replace if necessary.






Important!
Do not clean sealing surfaces with a metal-cutting tool.

Clean sealing surfaces with special tool 11 4 471 and 11 4 472.






Check fitting bush (1) for damage and correct seating.






Apply a sealing bead (1) on the lower crankcase section (see figure) with Loctite 5970 sealing compound.

Overview of consumable (2.2).

Installation note:
Follow manufacturer's instructions (Loctite).






Apply a sealing bead (1) on the top crankcase section (see figure) with Loctite 5970 sealing compound.

Installation note:
Follow manufacturer's instructions (Loctite).






Insert crankshaft (1).

Important!
Rotating component (danger of injury!)
Insert crankshaft with aid of a second person.
Weight of crankshaft approx. 19 kg.






Lubricate all bearings from 1 to 5 with engine oil.

Install crankcase lower section.






Tighten bolts (1 to 10).
Tightening torque: 11 11 1AZ.

Tighten bolts (11 to 28).
Tightening torque: 11 11 2AZ.

Tighten bolts exclusively with special tool 00 9 120.






Important!
Jointing torque and angle of rotation must be observed without fail.






To prevent oil leakage, apply a thin coating of Loctite 648 to cover sleeve (1) in area (2).

Overview of consumable (2.3).






Use special tool 23 1 240 to drive cover sleeves firmly to limit position.






Determine crankshaft side clearance.
Attach special tool 11 6 252 with the magnet.
Set special tool 11 6 251 to zero.
Press crankshaft in direction of arrow to the limit position.

Refer to Technical Data.






Replace radial shaft seal at front.
Replace radial shaft seal at rear.
Assemble engine.