11 21 001 Replacing crankshaft (B48, B46)

Special tools required: 

• 11 6 250
• 00 2 010
• 11 6 480

Attention  !

Replace main bearing and connecting rod bolts.

When replacing the crankshaft, the main bearing shells and connecting rod bearing shells must be replaced.

There must be no oil in the blind holes (risk of cracking). 

Do not  wash off bolt coating.

Incorrect assembly of the crankshaft bearing caps will result in damage to the crankcase.

Necessary preliminary tasks: 

• Remove BOTH TIMING CHAINS 
• Remove all PISTONS 
• Remove COUNTERBALANCE SHAFTS 

Removal: 

Check crankshaft SIDE CLEARANCE .

Fit special tool 11 6 250 .

If the permitted side clearance is exceeded:

• Check crankshaft and guide bearing shells.
• Replace worn components.

Fig 1: Checking Crankshaft Side Clearance

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Installation position must be maintained.

Fig 2: Crankshaft Bearing Caps

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Release main bearing screw connection of main bearing cap in the sequence 10 - 1. 

Remove main bearing caps 1 - 5.

Fig 3: Crankshaft Main Bearing Cap Screws Loosening/Tightening Sequence

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Attention  !

With the assistance of a second person, remove crankshaft and carefully place to one side.

Pay attention to oil hole in bearing shell.

Pay attention to installation position of CRANKSHAFT MAIN BEARING SHELLS .

Fig 4: Crankshaft Main Bearing Shells

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Installation: 

For new crankshaft replace CRANKSHAFT MAIN BEARING SHELLS .

Oil bearing shells (1 - 5).

Both locating grooves of bearing shells in crankcase and on crankshaft bearing cap must be mounted on one side.

Fig 5: Oil Bearing Shells

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Insert crankshaft (1).

Fig 6: Crankshaft Main Bearing Shells

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Attention  !

Do not fit crankshaft bearing cap in incorrect position.

Risk of damage to molding on crankcase.

Align crankshaft bearing cap exactly.

Fit main bearing bolts.

Tighten main bearing bolts in sequence 1 - 10  (comply with tightening specifications).

Tightening torque: 11 11 1AZ

Fig 7: Crankshaft Main Bearing Cap Screws Loosening/Tightening Sequence

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Check SIDE CLEARANCE .

Fig 8: Checking Crankshaft Side Clearance

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COEFFICIENT OF FRICTION of crankshaft.

Screw in all screws of vibration damper by hand.

Turn crankshaft evenly with special tool 00 2 010 and special tool 11 6 480 .

Fig 9: Turning Crankshaft Evenly With Special Tool (00 2 010) And (11 6 480)

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