Crankshaft Main Bearing: Service and Repair

11 21 531 - Replacing all crankshaft main bearings (S85)





Important!
1. - Repair: crankcase used / crankshaft used.
If the bearing channel is opened and closed again after engine operation, all main bearing shells must be replaced with special repair bearing shells.
Altered settling behaviour at the crankcase.
Repair bearing shells are marked with an (R) on their backs.
2. - Repair: crankcase used / crankshaft new.
Repair bearing shells marked with (R) must be used.
The crankshaft comes as a set together with the bearing shells. The bearing shells for the bedplate are provided in accordance with the crankshaft classification. For the crankcase bearing shells, the green bearing shells are always provided. The half classification is retained.
3. - Repair: crankcase new / crankshaft used.
Use the bearing shells which are also designated for initial installation without the letter (R) on the bearing back.
The crankcase comes as a set together with the bearing shells. The bearing shells for the crankcase are provided in accordance with the crankcase classification. For the bedplate, the green bearing shells are always provided. The half classification is retained.
4. - Repair: crankcase new / crankshaft new.
The bearing shells also designated for initial installation must be used.
Use the bearing shells which are also designated for initial installation without the letter (R) on the bearing back.
The crankcase comes as a set together with the bearing shells. The bearing shells for the crankcase are provided in accordance with the crankcase classification. For the bedplate, the green bearing shells are always provided. The half classification is retained.





Necessary preliminary tasks:
- Engine Removing and Installing Engine removed
- Remove crankshaft Service and Repair.





Installation Note:
Bearing shell (1) is a guide bearing.

Remove bearing shells (1) and (2).

Observe bearing classification.





Lay step bearing (1) on 6th bearing block.





Installation Note:
Bearing shell (1) with lubricant groove must be fitted in crankcase upper section.
Bearing shell (2) without lubricant groove must be fitted in crankcase lower section (bedplate).





Bearing classification on bedplate bearing seat.
Observe colour allocation on crankshaft (1 to 6).
V= - Violet.
G = - Green.
Y = - Yellow.





Bearing classification on crankcase bearing seat.
Observe colour allocation in crankcase (1 to 6).
V= - Violet.
G = - Green.
Y = - Yellow.





Assemble engine.