11 28 020 Replacing tensioning device for alternator drive belt (M57T2)

Necessary preliminary tasks: 

• Remove fan cowl. See 17 11 035 REMOVING AND INSTALLING/REPLACING FAN COWL WITH ELECTRIC FAN (M57T2) .
• Remove PRESSURE PIPE  (intercooler to EGR valve)
• Remove ALTERNATOR

Release screw (1) and remove pulley (2).

Release screw (3) and remove tensioning pulley with lever (4) in direction of arrow.

Fig 1: Removing Tensioning Pulley With Lever

Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

Remove belt tensioner in direction of arrow.

Installation 

Replace seal (2).

Fig 2: Removing Belt Tensioner

Courtesy of BMW OF NORTH AMERICA, INC.