Crankshaft Main Bearing: Service and Repair

11 21 531 Replacing all crankshaft main bearings (N 14)

Special tools required:
^ 11 4 470

Important:
Modified assignment of bearings.
Bearing (1) is at the output end (clutch end)
Determine main bearing colours; the designations on the crankcase and crankshaft are always required and can only determined using the table.

Necessary preliminary tasks:
^ Remove crankshaft.

Installation:
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 (bed plate).





Important:
Modified assignment of bearings.
Bearing (1) is at the output end (clutch end)

Bearings (1 to 5).
Bearing (2) is a guide bearing.

Important:
Clean sealing surfaces.
Do not clean sealing faces with a metal cutting tool.

Clean sealing faces with special tool 11 4 470 only.





Insert guide rings (1) in crankcase at bearing block (2) with groove facing outwards.
If necessary, attach with engine oil to crankcase.





Important:
Modified assignment of bearings.
Bearing (1) is at the output end (clutch end)

Bearings (1 to 5).

Important:
Clean sealing surfaces.
Do not clean sealing faces with a metal-cutting tool.

Clean sealing faces with special tool 114 470 only.





Bearing classification on crankcase upper half:
Bearing allocation 1-5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the color code.
Example:
Bearing 1. Letter P
Bearing 2. Letter K
Bearing 3. Letter I
Bearing 4. Letter N
Bearing 5. Letter N





Bearing classification on crankcase upper half:
Bearing allocation 1-5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the color code.
Example:
Bearing 1. Letter T
Bearing 2. Letter Q
Bearing 3. Letter Q
Bearing 4. Letter R
Bearing 5. Letter R








Crankshaft bearing colours:
BL= Blue.
SW= Black.
Gr= Green.
Ge Yellow.
Or Orange.

Bearing classification on crankcase lower half:
Bearing allocation 1-5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the color code.
Example:
Bearing 1. Letter P
Bearing 2. Letter K
Bearing 3. Letter I
Bearing 4. Letter N
Bearing 5. Letter N





Bearing classification on crankcase lower half:
Bearing allocation 1-5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the color code.
Example:
Bearing 1. Letter T
Bearing 2. Letter Q
Bearing 3. Letter Q
Bearing 4. Letter R
Bearing 5. Letter R









Crankshaft bearing colours:
BL= Blue.
SW= Black.
Gr= Green.
Ge Yellow.
Or Orange.

Example: Crankcase upper half:
Combining the dots of the designations of the crankshaft and crankcase produces the following color combinations.
Bearing 1: The letters (P and T) produce in the crankcase upper half the color Ge= Yellow with lubricant groove.
Bearing 2: K and Q= Ge= Yellow.
Bearing 3: I and Q= Ge= Yellow.
Bearing 4: N and R= Gr= Green.
Bearing 5: N and R= Gr= Green.





Example: Crankcase lower half:
Combining the dots of the designations of the crankcase and crankshaft produces the following color combinations.
Bearing 1: The letters P. and T. produce in the crankcase lower half the color Gr= Green without lubricant groove.
Bearing 2: K and Q= Gr= Green.
Bearing 3: I and Q= Gr= Green.
Bearing 4: N and R= Gr= Green.
Bearing 5: N and R= Gr= Green.





Check spray nozzle (2) for damage, replace if necessary.
Release screw (1).

Tighten Oil spray nozzle to crankcase upper section
8AZ Oil spray nozzle to crankcase upper section
M10 20 Nm

Remove oil spray nozzle (2).
Installation:
Oil spray nozzle (2) is turned when screw (1) is tightened and then rests with its upper corner against crankcase.





Install crankcase lower section.
Assemble engine.