Crankshaft: Service and Repair

11 21 500 - Replacing crankshaft (S85)





Special tools required:
- 00 9 120 00 9 120 Torque Angle Measuring Dial
- 00 9 130 00 9 130 Magnet with 1/2 " Connection
- 11 4 370 11 4 370 Pressing Fixture
- 11 9 360 11 9 360 Drift





Important!
Unscrew all M8 fit bolts first before releasing the crankshaft lower section.

Altered settling behaviour at the crankcase!

If the main bearing channel is opened after engine operation, all main bearing shells must be replaced with special repair bearing shells marked with an (R).

There are two different groups of main bearing shells.





Necessary preliminary tasks:
- Remove engine Removing and Installing Engine.
- Mount engine on assembly stand 11 00 ... Mounting Engine on Assembly Stand.
- Remove flywheel Removing and Installing / Replacing Flywheel (S85 7-Speed SMG).
- Remove vibration damper Service and Repair.
- Removing oil sump Service and Repair.
- Remove engine oil pump Service and Repair.
- Remove VANOS high-pressure pump Removing and Installing / Replacing VANOS High-Pressure Pump (S85).
- Remove cylinder head on left and right.
- Remove all pistons Service and Repair.
- Remove both timing chains.





Important!
Unscrew all M8 fit bolts (2) first before releasing the crankshaft lower section - risk of damage!

Release all bearing block bolts (1) from inside outwards.

Installation Note:
Replace fine-mesh strainer (3).





Release screws (3).

Unfasten screws (2).

Bolts (1) from inside outwards.

Lift out bedplate.





Lever out crankshaft (1) with aid of a second person in direction of arrow.

Note:
Weight of crankshaft approx. 22 kg.





Important!
If the bedplate is opened and closed again, fit special main bearing shells marked with (R) on the bearing backs.

Replace all bearing shells (1 and 2).

Installation Note:
Replace main bearing shells Service and Repair.





Remove sealing compound from joint (1).

Carefully clean threads and contact faces in upper and lower sections of crankcase.

Installation Note:
Replace nozzles (2).





Installation Note:
Apply a light coating of engine oil to bearing shells.

Lay crankshaft (1) with a second person helping in direction of arrow into crankcase.

Note:
Weight of crankshaft approx. 22 kg.





Important!
Adhere without fail to the specified sequence of bedplate bolt connections.

Risk of damage to crankshaft.

Leaks at bedplate/crankcase.





Note:
There are no more dowel sleeves in the crankcase.

Position bedplate on crankcase.

Important!
Do not use new bolts.

If new bolts are used, observe special tightening/torque specifications.

Position lower section diagonally on bearing blocks (1 and 6) using two fit bolts (1).

Join fit bolts (1) to 8 Nm.





Insert all M11 bolts (1).







Tightening sequence of M11 and then M8 fit bolts
Bearing blocks (1 to 6).

Tightening sequence (1 to 12).





Tighten M11 bolts with special tools 00 9 120 00 9 120 Torque Angle Measuring Dial and 00 9 130 00 9 130 Magnet with 1/2 " Connection.

Tightening torque: 11 11 1AZ 11 11 Engine Block.

Observe tightening/torque sequence.





Insert fit bolts (1) and initially tighten without play.

Tightening torque: 11 11 2AZ 11 11 Engine Block





Tighten fit bolts with special tools 00 9 120 00 9 120 Torque Angle Measuring Dial and 00 9 130 00 9 130 Magnet with 1/2 " Connection.

Tightening torque: 11 11 2AZ. 11 11 Engine Block





Insert bolts (1).

Tightening torque: 11 11 3AZ. 11 11 Engine Block

Insert bolts (2).

Tightening torque: 11 11 4AZ. 11 11 Engine Block

Insert bolts (3).

Tightening torque: 11 11 5AZ. 11 11 Engine Block





Drive in both nozzles with special tool 11 9 360 11 9 360 Drift on left and right into crankcase.

Installation Note:
Always replace nozzles.





Installation Note:
Use primer 1.5 and liquid gasket 1.6 Procedures.

Prepare liquid gasket (2) in special tool 11 4 370.

Screw on nozzle (1) for injecting liquid gasket.





Press sealing compound nozzle in direction of arrow onto nozzle at 90°.

Slowly and evenly insert sealing compound (1) with special tool 11 4 370 11 4 370 Pressing Fixture in direction of arrow.





Stop (seal off) escaping liquid gasket with primer 1.5 at outlet bore (1).

Install radial shaft seal at front Service and Repair.

Install radial shaft seal at rear Service and Repair.





Assemble engine.