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Home >> BMW >> 2009 >> 528i Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> Remove, Overhaul & Install >> Engine Electrical System - Repair >> Alternator With Drive And Mounting >> 12 31... Replacing alternator belt pulley
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12 31... Replacing alternator belt pulley

Special tools required: 

PROCEDURE WITH SPECIAL TOOL 12 7 121 

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 .

Remove alternator drive belt.

Release screw and if necessary remove freewheel.

Fig 1: Identifying Special Tool (12 7 121) And (12 7 122)
G04751318Courtesy of BMW OF NORTH AMERICA, INC.
Fig 2: Identifying Special Tool (12 7 123)
G00526767

PROCEDURE WITH SPECIAL TOOL 12 7 123 

Depending on the alternator version, hold down alternator axis with: Torx key and Hold inner multi-wrench tool (special tool 12 7 122).

Release freewheel with special tool 12 7 123 and a ring spanner and remove. Installation note:  Tightening torque 12 31 8AZ .