12 31 ... Replacing alternator belt pulley

Special tools required: 

• 12 7 110

Remove and install alternator drive belt.

Depending on alternator type, grip shaft with:

• hexagon socket
• multi-tooth socket or
• Torx socket wrench

Release nut with special tool 12 7 110.

Fig 1: Removing Alternator Drive Belt

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

Tightening torque, 12 31 2AZ / 12 31 3AZ. Refer to ENGINE ELECTRICAL SYSTEM - TIGHTENING TORQUES .