Necessary preliminary work

Remove CRANKSHAFT

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

Fig 1: Identifying Main Bearing Caps Marked Numbers

Courtesy of BMW OF NORTH AMERICA, INC.

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 Color Assignment On Crankshaft 1 To 5

Courtesy of BMW OF NORTH AMERICA, INC.

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 Color Assignment In Crankcase 1 To 5

Courtesy of BMW OF NORTH AMERICA, INC.

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 Color Assignment On Crankshaft 1 To 5

Courtesy of BMW OF NORTH AMERICA, INC.

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

BEARING SHELL CLASSIFICATION LETTER WITH CODE

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

TOLERANCE CLASSES AND BEARING SHELL COVERS COLOR CODE REFERENCE CHART

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

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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 Main Bearing Cap Thrust Washers Surfaces

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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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