11 21 500 Replacing crankshaft (N55)

Special tools required:

IMPORTANT: Aluminum screws/bolts are permitted with and without color coding (blue).
Aluminum screws/bolts must be replaced each time they are released .
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 ENGINE .
Mount engine on ASSEMBLY STAND.
Remove VIBRATION DAMPER .
Remove oil sump . See 11 13 000 REMOVING AND INSTALLING, SEALING OR REPLACING OIL SUMP (N55) .
Remove OIL PUMP .
Remove timing CHAIN MODULE .
Remove oil pump/vacuum pump CHAIN MODULE .
Remove CYLINDER HEAD .
Remove FLYWHEEL .
Removing all PISTONS .

Release screws (1).

Tightening torque: 11 13 5AZ .

Installation note:

Replace aluminum screws.

Remove oil deflector with integrated intake snorkel.

Fig 1: Removing Oil Deflector

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Release aluminum screws (1).

Release aluminum screws (2).

Installation note:

Replace aluminum screws.

Fig 2: Identifying Oil Deflector Aluminum Screws

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Release aluminum screws (1).

Installation note:

Replace aluminum screws.

NOTE: Graphic shows N52.

Fig 3: Identifying Crankcase Lower Section Screws

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Release screws (1).

Unfasten screws (2).

Installation note:

Replace aluminum screws.

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

Remove crankcase lower section upwards.

Fig 4: Identifying Crankcase Lower Section Steel Screws

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IMPORTANT: Remove crankshaft with aid of a second person.
Weight of crankshaft approx. 25 kilograms.

Remove crankshaft (1) upward in direction of arrow.

Remove BEARING SHELLS (2) and guide bearing shell (3), replace if necessary.

Fig 5: Removing Crankshaft

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Clean all sealing surfaces (1) with special tool 11 4 470 .

Fig 6: Identifying Bearing Shells Sealing Surfaces

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Check fitting sleeves for damage and secure seating; replace if necessary.

Install all BEARING SHELLS .

Installation note:

Oil all bearing points adequately with engine oil.

Fig 7: Identifying Bearing Shells Fitting Sleeves

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IMPORTANT: Insert crankshaft with aid of a second person.
Weight of crankshaft approx. 25 kilograms.

Insert crankshaft (1).

Fit crankcase lower section (watch fitting bushes).

Fig 8: Identifying Crankshaft

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Fig 9: Crankshaft Bolts Tightening/Loosening Sequence

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Follow tightening/torque sequence for the steel bolts (1 to 14).

JOIN steel bolts (1).

Fig 10: Tightening Crankshaft Steel Bolts

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Mark across all steel bolts (1) with a colored mark.

Fig 11: Crankshaft Steel Bolts Color Mark

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Tighten all steel bolts with a special tool 00 9 120 .

Tightening torque: 11 11 1AZ .

Installation note:

All steel bolts must be positioned the same with respect to the colored mark after being fastened (see Fig 9 ).

Fig 12: Tightening Crankshaft Steel Bolts Using Special Tool (00 9 120)

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Installation note:

Aluminum bolts (1) and (2) can have a blue colored mark.

Aluminum screws/bolts are not magnetic .

Fig 13: Identifying Crankshaft Aluminum Bolts With Colored Mark

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

JOIN all aluminum bolts (1) from inside toward the outside.

Tightening torque: 11 11 2AZ .

Fig 14: Tightening Crankshaft Aluminum Bolts

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Mark across all aluminum bolts (1) with a colored mark.

Fig 15: Crankshaft Aluminum Bolts Colored Mark

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Tighten all aluminum bolts (1) only with special tool 00 9 120 .

Tightening torque: 11 11 3AZ .

Tightening torque: 11 11 4AZ .

Installation note:

All aluminum bolts must be equally positioned with respect to the colored mark after being fastened.

Fig 16: Tightening Crankshaft Aluminum Bolts Using Special Tool (00 9 120)

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Fit special tool 11 6 252 with magnetic foot on special tool 11 4 440 .

Clamp special tool 11 6 251 on special tool 11 6 252 .

Position special tool 11 6 251 with button on the flat side of the crankshaft.

Press crankshaft (1) in direction of arrow up to stop.

Set dial gauge with knurled screw (2) on zero.

Fig 17: Pressing Crankshaft

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Press crankshaft (1) in direction of arrow from right to left up to stop.

Determine crankshaft axial clearance. See 1121 CRANKSHAFT AND BEARINGS (N55) .

Fig 18: Pressing Crankshaft

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Turn crankshaft (1) via the central bolt with special tool 00 2 010 to determine the coefficient of friction. See 1121 CRANKSHAFT AND BEARINGS (N55) .

Fig 19: Turning Crankshaft