11 21 531 Replacing All Main Crankshaft Bearing Shells (N52K)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2013 BMW 128i, 2012 BMW 128i, 2011 BMW 128i, 2010 BMW 128i, and 2009 BMW 128i. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

For the following special tools, refer to MAINTENANCE AND GENERAL INFORMATION - SPECIAL TOOLS -- 128I .

00 2 590

For the following special tools, refer to ENGINE- SPECIAL TOOLS (N52K) .

11 4 251
11 4 252
11 4 470

IMPORTANT: Aluminum-magnesium materials. No steel screws/bolts may be used due to the threat of electrochemical corrosion. A magnesium crankcase requires aluminum screws/bolts exclusively. Aluminum screws/bolts must be replaced each time they are released. Aluminum screws/bolts are permitted with and without color coding (blue). For reliable identification: Aluminum screws/bolts are not magnetic . Jointing torque and angle of rotation must be observed without fail (risk of damage) .

Necessary preliminary tasks:

Remove crankshaft . See 11 21 500 REPLACING CRANKSHAFT (N52K) .

Checking position of oil spray nozzles:

Insert special tool 11 4 251 in screw connection of main bearing.

NOTE: Special tool 11 4 252 must be pre-installed at the seventh main bearing.

Fig 1: Identifying Oil Spray Nozzle With Special Tools (11 4 251 And 11 4 252)

Courtesy of BMW OF NORTH AMERICA, INC.

Check position of oil spray nozzle (2) according to position (1) on special tool 11 4 251.

If necessary, adjust and secure oil spray nozzle (2).

Tightening torque. See 11 11 5AZ in 11 11 CRANKCASE .

Remove bearing shells (2) and guide bearing shell (3).

NOTE: Guide bearing shell (3) is a thrust bearing.
Observe bearing classification.

Fig 2: Removing Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Bearing shell (1) with lubricant groove must be fitted in crankcase.

Bearing shell (2) without lubricant groove must be fitted in bedplate.

Fig 3: Identifying Bearing Shells

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: It is not possible to remachine the crankshaft.

Surface (1) for marking.

Seven-digit part number (2).

Bearing classification (3).

Fig 4: Identifying Seven-Digit Part Number

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

The letter / number combination produces a bearing shell pairing. Identification by different colours.

IMPORTANT: Excessively small bearing play will result in engine damage.

Fig 5: Identifying Bearing Classification On Crankcase

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 6: Identifying Bearing Shell With/Without Lubricant Groove

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: First bearing point is on the timing drive. The colour combination Yellow and Red must not be fitted. Engine damage will result if excessively small bearing play is determined.

Code letters on crankcase:

Code letter A = bearing shell (1) colour Yellow.

Code letter B = bearing shell (1) colour Green.

Code letter C = bearing shell (1) colour Red.

Code numbers on crankshaft:

Code number 1 = bearing shell (2) Yellow.

Code number 2 = bearing shell (2) Green.

Code number 3 = bearing shell (2) Red.

IMPORTANT: The colour combination Yellow and Red must not be fitted; the bearing colours Green / Green must be selected for this colour combination

Installation example:

For bearing 1 with code letter A on the crankcase and code number 1 on the crankshaft bearing shell (1) with the colour Yellow is required for the crankcase and bearing shell (2) with the colour Yellow for the crankcase lower half (bedplate).

Bearing 2: A and 2 colours Yellow and Green.

Bearing 3: B and 2 colours Green and Green.

Bearing 4: C and 2 colours Red and Green.

Bearing 5: B and 1 colours Green and Yellow.

Bearing 6: C and 3 colours Red and Red.

Bearing 7: C and 1 colours Green and Green.

The colour combination Yellow and Red must not be fitted.

Possible color combinations (see COLOR COMBINATIONS FOR MOUNTING CRANKSHAFT ).

COLOR COMBINATIONS FOR MOUNTING CRANKSHAFT

(A 1) Crankcase/Yellow	(B 1) Crankcase/Green	(C 1) Crankcase/Green
(A 1) Crankcase lower half/Yellow	(B 1) Crankcase lower half/Yellow	(C 1) Crankcase lower half/Green
(A 2) Crankcase/Yellow	(B 2) Crankcase/Green	(C 2) Crankcase/Red
(A 2) Crankcase lower half/Green	(B 2) Crankcase lower half/Green	(C 2) Crankcase lower half/Green
(A 3) Crankcase/Green	(B 3) Crankcase/Green	(C 3) Crankcase/Red
(A 3) Crankcase lower half/Green	(B 3) Crankcase lower half/Red	(C 3) Crankcase lower half/Red

Install bearing shells (2) and guide bearing shell (3).

Installation:

Clean all sealing surfaces.

IMPORTANT: Do not use any metal-cutting tools.

Fig 7: Installing Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Clean sealing faces with special tool 11 4 470 only.

Determine bearing play with special tool 00 2 590.

Installation:

All measuring points must be clean and free from oil and grease. If necessary, clean all measuring points.

Use the existing screws to determine the bearing play.

Set up bedplate with bearing shells.

Remove bedplate.

Read off bearing play at width of flattened plastic thread and measurement scale.

Installation:

Remove plastic thread.

Apply a light coat of oil to bearing shells and crankshaft.

Fig 8: Measuring Bearing Play Width

Courtesy of BMW OF NORTH AMERICA, INC.

Install bedplate.

Assemble engine.