Crankshaft Main Bearing: Service and Repair
11 21 531 Replacing all crankshaft main bearings (N12)Special tools required:
Important!
Modified assignment of bearing positions.
Bearing position (1) is at the output end (clutch end)
Determine main bearing colors; the designations on the crankcase and crankshaft are always required and can only determined using the table.
Necessary preliminary work:
^ Remove crankshaft.
Installation note:
Bearing shell (1) with lubricating groove must be fitted in crankcase upper part.
Bearing shell (2) without lubricating groove must be fitted in crankcase lower section (bedplate).
Important!
Modified assignment of bearing positions.
Bearing position (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 surfaces with a metal cutting tool.
Only use special tool 11 4 470 to clean sealing surfaces.
Insert guide rings (1) in crankcase at bearing seat (2) with groove facing outwards.
If necessary, attach with engine oil to crankcase.
Important!
Modified assignment of bearing positions.
Bearing position (1) is at the output end (clutch end)
Bearings (1 to 5).
Important!
Clean sealing surfaces.
Do not clean sealing surfaces with a metal cutting tool.
Only use special tool 11 4 470 to clean sealing surfaces.
Bearing classification on crankcase upper part:
Bearing allocation 1 - 5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the colour code.
Example:
Lager 1. Letter P
Lager 2. Letter K
Lager 3. Letter I
Lager 4. Letter N
Lager 5. Letter N
Bearing classification on crankcase upper part:
Bearing allocation 1 - 5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the colour code.
Example:
Lager 1. Letter T
Lager 2. Letter Q
Lager 3. Letter Q
Lager 4. Letter R
Lager 5. Letter R
Crankshaft bearing colors:
BL= Blue.
SW= Black.
Gr= Green.
Ge Yellow.
Or Orange.
Bearing classification on crankcase lower section:
Bearing allocation 1 - 5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the colour code.
Example:
Lager 1. Letter P
Lager 2. Letter K
Lager 3. Letter I
Lager 4. Letter N
Lager 5. Letter N
Bearing classification on crankcase lower section:
Bearing allocation 1 - 5: the designations on the crankcase and crankshaft are always required.
Refer to the table for the colour code.
Example:
Lager 1. Letter T
Lager 2. Letter Q
Lager 3. Letter Q
Lager 4. Letter R
Lager 5. Letter R
Crankshaft bearing colors:
BL= Blue.
SW = Black.
Gr = Green.
Ge = Yellow.
Or = Orange.
Example: Crankcase upper part:
Combining the dots of the designations of the crankshaft and crankcase produces the following colour combinations.
Bearing 1: The letters (P and T) produce in the crankcase upper part the colour Ge= Yellow with lubricating 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 section:
Combining the dots of the designations of the crankcase and crankshaft produces the following colour combinations.
Bearing 1: The letters P. and T. produce in the crankcase lower section the colour Gr= Green without lubricating 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.
Install crankcase lower section.
Assemble engine.