12 31... Replacing alternator belt pulley (with overrunning clutch)

Special tools required: 

• 12 7 120

Remove and install alternator drive belt.

Grip alternator shaft with:

• internal serration

Release nut with special tools 12 7 120.

Installation: 

Tightening torque 12 31 3AZ.

Fig 1: Removing/Installing Alternator Pulley

Courtesy of BMW OF NORTH AMERICA, INC.