11 21 531 Replacing all crankshaft main bearing shells (S63)

Special tools required: 

• 00 2 590
• 00 9 120
• 11 6 251
• 11 6 252

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

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

1. Y = yellow
2. G = green
3. V = violet
   Fig 2: Identifying Color Assignment On Crankshaft

   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.

1. Y = yellow
2. G = green
3. V = violet
   Fig 3: Identifying Bearing Position In Crankcase

   Courtesy of BMW OF NORTH AMERICA, INC.

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

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 C M N P q R	Green Green	Crankshaft	I C M N P q R	Green Green
Crankcase	S T U W X Z	Violet	Crankshaft	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.

Turn back thread support bushing into main bearing cap.

Checking main bearing clearance 

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

Do not twist crankshaft.

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

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

Tightening torque 11 11 1 AZ. .

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

Remove main bearing cap.

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

Main bearing play.

• Remove plastic thread
• Apply a coat of oil to new bearing shells and crankshaft
  Fig 11: Measuring Main Bearing Clearance Using Measurement Scale

  Courtesy of BMW OF NORTH AMERICA, INC.

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.

Assemble engine.