11 21 500 Replacing crankshaft (N51)

Special tools required:

00 2 510
00 9 120
11 4 370
11 4 440
11 9 360

IMPORTANT: Aluminium-magnesium materials.

No steel screws/bolts may be used due to the threat of electrochemical corrosion.

A magnesium crankcase requires aluminium screws/bolts exclusively.

Aluminium screws/bolts must be replaced each time they are released .

Aluminium screws/bolts are permitted with and without color coding (blue).

For reliable identification:

Aluminium screws/bolts are not magnetic .

Jointing torque and angle of rotation must be observed without fail (risk of damage).

Necessary preliminary tasks:

Remove Engine
Mount engine on Assembly Stand
Remove Vibration Damper
Remove Oil Pan.
Remove Oil Pump
Remove oil pump/vacuum pump Chain Module
Remove Timing Chain Module
Remove Cylinder Head
Remove Flywheel
Removing All Pistons

Release screws (1).

For tightening torque refer to 11 13 5AZ in 11 13 OIL PAN .

Installation:

Replace aluminium screws.

Remove oil deflector (2).

Fig 1: Oil Deflector And Mounting Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

For tightening torque refer to 11 11 2AZ in 11 11 CRANKCASE .

Release screws (2).

For tightening torque refer to 11 11 3AZ in 11 11 CRANKCASE .

Installation:

Replace aluminium screws.

Fig 2: Cylinder Block Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

For tightening torque refer to 11 11 1AZ in 11 11 CRANKCASE .

Release screws (2).

For tightening torque refer to 11 11 4AZ in 11 11 CRANKCASE .

Installation:

Replace aluminium screws.

Release steel screws (1 to 14) from outside inwards.

For tightening torque refer to 11 11 1AZ in 11 11 CRANKCASE .

Fig 3: Crankcase Bolts Tightening/Loosening Sequence

Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

For tightening torque refer to 11 11 3AZ in 11 11 CRANKCASE .

Installation:

Replace aluminium screws.

Remove crankcase lower section in upward direction.

Fig 4: Engine Bedpan Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Remove crankshaft (1) in direction of arrow.

IMPORTANT: Remove crankshaft with aid of a second person.

Weight of crankshaft approx. 25 kg.

Remove Bearing Shells (2) and guide bearing shell (3), replace if necessary.

Clean all sealing faces with special tool 11 4 470.

Fig 5: Bearing Shells, Crankshaft, Removal Direction And Guide Bearing Shell

Courtesy of BMW OF NORTH AMERICA, INC.

Check adapter sleeves (1) for damage and secure seating; replace if necessary.

Install all Bearing Shells

Installation:

Lubricate all bearing points with engine oil.

NOTE: Picture shows N46.

Fig 6: Adapter Sleeves

Courtesy of BMW OF NORTH AMERICA, INC.

Insert crankshaft (1).

IMPORTANT: Install crankshaft with aid of a second person.

Weight of crankshaft approx. 25 kg.

Fig 7: Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Tighten steel screws (1 to 14) from inside outwards.

For tightening torque refer to 11 11 1AZ in 11 11 CRANKCASE .

Tighten screws (2) from inside outwards.

For tightening torque refer to 11 11 4AZ in 11 11 CRANKCASE .

Tighten screws (1).

For tightening torque refer to 11 11 2AZ in 11 11 CRANKCASE .

Installation:

Replace aluminium screws.

Fig 8: Crankcase Bolts Tightening/Loosening Sequence

Courtesy of BMW OF NORTH AMERICA, INC.

Tighten aluminium screws exclusively with special tool 00 9 120.

IMPORTANT: In the case of aluminium screws, jointing torque and angle of rotation must be observed without fail.

Fig 9: Special Tool (00 9 120)

Courtesy of BMW OF NORTH AMERICA, INC.

Set up stand with magnetic foot (1) on special tool 11 4 440.

Set up special tool 00 2 510 on stand.

Position special tool 00 2 510 on crankshaft.

Move crankshaft in direction of arrow.

Determine Bearing Play .

Fig 10: Special Tools (00 2 510), (11 4 440) And Magnetic Foot

Courtesy of BMW OF NORTH AMERICA, INC.

Drive in both nozzles (1) with special tool 11 9 360 on left and right into crankcase.

Installation:

Always replace nozzles (1).

Fig 11: Special Tool (11 9 360) And Nozzles

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Prepare sealing compound (1) in special tool 11 4 370.

Screw on nozzle (2) for injecting sealing compound.

Slowly insert sealing compound (1) with special tool 11 4 370 in direction of arrow.

Fig 12: Identifying Special Tool (11 4 370)

Courtesy of BMW OF NORTH AMERICA, INC.

Replace radial shaft seal at Front.

Replace radial shaft seal at Rear.

Assemble engine.