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Home >> BMW >> 2007 >> 335i 2D Convertible, Automatic >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Engine Electrical System -- Repair (N54) >> 31 Alternator With Drive >> 12 31 ... Replacing Alternator Belt Pulley
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12 31 ... Replacing Alternator Belt Pulley

Special tools required: 

Remove and install alternator drive belt.

Depending on alternator type, grip shaft with:

Release nut with special tool 12 7 110.

Installation: 

Tightening torque, 12 31 2AZ/12 31 3AZ, see ENGINE ELECTRICAL SYSTEM -- TORQUE SPECIFICATIONS -- TWIN TURBO .

Fig 1: Identifying Special Tool (12 7 110)
G04740393Courtesy of BMW OF NORTH AMERICA, INC.


Special tools required: 

Illustrations show N42:

If fitted, remove cover cap from belt pulley.

Depending on alternator type, slacken screw with:

Grip freewheel with special tool 12 7 121.

Installation: 

Tightening torque 12 31 8AZ, see ENGINE ELECTRICAL SYSTEM -- TORQUE SPECIFICATIONS -- TWIN TURBO .

Remove alternator drive belt.

Release screw and if necessary remove freewheel.

Fig 1: Identifying Special Tool (12 7 121) On Freewheel
G04751318Courtesy of BMW OF NORTH AMERICA, INC.