12 31... Replacing alternator belt pulley

Special tools required: 

• 12 7 110  , see ENGINE ELECTRICAL SYSTEM - SPECIAL TOOLS (N54, N63) .

Remove and install alternator drive belt.

Depending on alternator type, grip shaft with:

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

Fig 1: Installing Alternator Drive Belt

Courtesy of BMW OF NORTH AMERICA, INC.

Release nut with special tool 12 7 110.

Installation: 

Tightening torque, 12 31 2AZ / 12 31 3AZ  , see 12 31 ALTERNATOR WITH DRIVE AND MOUNTING PARTS .