Replacing tensioning device for alternator drive belt (S55 engine)

Special tools required: 

• 11 0 390

Necessary preliminary work: 

• Remove DRIVE BELT .

Remove special tool 11 0 390.

Release screw (1) on belt tensioner.

Tightening torque 11 28 1AZ .

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.