Crankshaft Main Bearing: Service and Repair

11 21 531 Replacing All Crankshaft Main Bearings (N16)

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.
A different bearing classification is necessary at bearing seat 5 on account of the central bolt on the timing chain drive.







Necessary preliminary tasks:
- Remove crankshaft.







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).







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.







Bearing classification on crankcase upper and lower sections:

Bearing allocation 1 - 5: the designations on the 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 and lower sections:

Bearing allocation 1 - 5: the designations on the crankcase 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


Example: Crankshaft / crankcase.

Bearing (1):
Letter P on the crankshaft and letter T on the crankcase correspond to bearing colour codes for the crankcase Or= orange with lubricating groove.
Letter P on the crankshaft and letter T on the crankcase correspond to bearing colour codes for the crankcase lower section (bedplate) Ge= yellow without lubricating groove.

Bearing (2):
Letter K on the crankshaft and letter Q on the crankcase correspond to bearing colour codes for the crankcase Or= orange with lubricating groove.
Letter K on the crankshaft and letter Q on the crankcase correspond to bearing colour codes for the crankcase lower section (bedplate) Or= orange without lubricating groove.

Bearing (3):
Letter I on the crankshaft and letter Q on the crankcase correspond to bearing colour codes for the crankcase Or= orange with lubricating groove.
Letter I on the crankshaft and letter Q on the crankcase correspond to bearing colour codes for the crankcase lower section (bedplate) Or= orange without lubricating groove.

Bearing (4):
Letter N on the crankshaft and letter R on the crankcase correspond to bearing colour codes for the crankcase Ge= yellow without lubricating groove.
Letter N on the crankshaft and letter R on the crankcase correspond to bearing colour codes for the crankcase lower section (bedplate) Ge= yellow without lubricating groove.

Attention: See extra table.

Bearing (5):
Letter N on the crankshaft and letter R on the crankcase correspond to bearing colour codes for the crankcase Ge= yellow with lubricating groove.
Letter N on the crankshaft and letter R on the crankcase correspond to bearing colour codes for the crankcase lower section (bedplate) Gr= green without lubricating groove.







Crankshaft bearing colors, bearing positions 1-4

Sw = Black.
Gr = Green.
Ge = Yellow.
Or = Orange.
Br = Brown.















Crankshaft bearing colors, bearing position 5:
Sw = Black.
Gr = Green.
Ge = Yellow.
Or = Orange.
Br = Brown (only in crankcase upper section).















Install crankcase lower section.
Assemble engine.