11 21 531 Replacing all crankshaft main bearing shells (N63)

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Special tools required:

IMPORTANT: Risk of injury from sharp edge of housing.

IMPORTANT: If a crankcase or a crankshaft is replaced, old and new identifications can be used.
A mixed installation is permissible.
Example:
An old crankcase with an old crankcase designation and a new crankshaft with a new crankshaft designation.
An old crankshaft with an older crankshaft designation and a new crankcase with a new crankcase designation.
Or a new crankcase with a new crankshaft with new identifications.

Necessary preliminary tasks:

Remove CRANKSHAFT

NOTE: The main bearing caps 1 to 5 are marked with numbers.

Fig 1: Identifying Main Bearing Caps

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Observe crankshaft construction stage:

S: Series

B: Repair stage 1

C: Repair stage 2

The letters denote the bearing shell classification for the relevant bearing position from 1 to 5 (main bearing cap).

The first letter on the left applies to the first bearing position at the front on the timing chain drive.

Color assignment on crankshaft 1 to 5

Y= yellow

G= green

V= violet

Fig 2: Identifying Bearing Shell Classification Letters (Main Bearing Cap)

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The letters denote the bearing shell classification for the relevant bearing position from 1 to 5 in the crankcase and is located on the transmission side in the Vee. The first letter on the left applies to the first bearing position at the front on the timing chain drive.

Color assignment in crankcase 1 to 5.

Y= yellow

G= green

V= violet

Fig 3: Identifying Bearing Shell Classification Letters (Crankcase)

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IMPORTANT: New bearing shell classification.

The letters denote the bearing shell classification for the relevant bearing position from 1 to 5 (main bearing cap).

The first letter on the left applies to the first bearing position at the front on the timing chain drive.

Color assignment on crankshaft 1 to 5

Fig 4: Identifying Bearing Shell Classification Letters (Main Bearing Cap)

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Changed bearing classification:
Bearing position 1, 2, 3, 4 and 5

Code letter	Color code
New (A to H) Old Y	Yellow Yellow
New (I to R) Old G	Green Green
New (S is Z) Old V	Violet

	Tolerance classes	Bearing shell covers		Tolerance classes	Bearing shell covers
Crankcase	A B C D E G H	Yellow Yellow	Crankshaft	A B C D E G H	Yellow Yellow
Crankcase	I K M N P q R	Green Green	Crankshaft	I K M N P q R	Green Green
Crankcase	S T U W X Z-Series	Violet	Crankshaft	S T U W X Z-Series	Violet

Installation note:

Install main bearing shells (1) with lubrication groove in crankcase.

Install main bearing shells (2) without lubrication groove in the main bearing caps.

Fig 5: Identifying Main Bearing Shells With Lubrication Groove And Main Bearing Shells Without Lubrication Groove

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NOTE: Main bearing cap number 3 can be identified by the surfaces (1) for the thrust washers of the thrust bearing.

Fig 6: Identifying Surface For Thrust Washer

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Turn back thread support bushing into main bearing cap.

Fig 7: Turning Back Thread Support Bushing Into Main Bearing Cap

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Checking main bearing clearance:

To check crankshaft bearing play, use the existing main bearing bolts.

IMPORTANT: Risk of cracking!
No oil is permitted in the blind holes.

Do not twist crankshaft.

Place special tool 00 2 590 (Plastigage model PG 1) onto the oil-free crankshaft (see arrow).

Fig 8: Checking Crankshaft Bearing Play

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Tighten down all collar bolts (M11) of main bearing caps in sequence 1 to 5 to jointing torque.

Tightening torque 11 11 1AZ .

Fig 9: Crankshaft Bolts (M11) Tightening/Loosening Sequence (N63)

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Tighten down all collar bolts (M11) of main bearing caps with special tool 00 9 120 with angle of rotation.

Fig 10: Tightening Collar Bolts Of Main Bearing Caps

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Remove main bearing cap.

Read off main bearing clearance at width of flattened plastic thread with assistance of measurement scale.

Refer to MAIN BEARING PLAY .

Remove plastic thread
Apply a coat of oil to new bearing shells and crankshaft

Fig 11: Determining Radial Clearance
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NOTE: Always replace main bearing bolts in main bearing caps with new bolts.
Do not wash off bolt coating.

IMPORTANT: Risk of cracking!
No oil is permitted in the blind holes.

Install CRANKSHAFT .

Carefully strike back and front of crankshaft with a plastic hammer to center guide bearing (do not damage crankshaft).

Secure special tool 11 6 252 with magnetic foot on crankcase.

Position special tool 11 6 251 .

Tightening specifications for main bearing:

Check AXIAL PLAY .

Check guide bearing shell, crankshaft and crankcase if necessary.

Fig 12: Checking Axial Play

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Assemble engine.