12 31 020 Removing and installing or replacing alternator (N55)

WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary work:

Switch off ignition
Disconnect BATTERY EARTH LEAD and cover.
Remove front CHARGE-AIR DUCT .
Remove rear CHARGE-AIR DUCT .
Remove alternator DRIVE BELT .

NOTE: In order to remove the alternator, it is necessary to REMOVE the air conditioning compressor .

In so doing:

Do not draw off A/C system refrigerant.
Do not detach refrigerant lines from A/C compressor.
Do not remove air conditioning compressor; instead, release from holder only and place to one side.

Release screws (1).

Tightening torque: 12 31 1AZ .

Release screw (2).

Tightening torque: 12 31 2AZ .

Release screw (3) and remove with holder (4).

Tightening torque: 12 31 2AZ .

Fig 1: Identifying Alternator Holder With Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Unlock connector (1) and remove.

Remove protective cap (2) and release nut underneath.

Tightening torque: 12 42 1AZ .

Remove positive battery cable(3).

Fig 2: Identifying Protective Cap And Connector

Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: For purposes of improved clarity, illustrations and description show A/C compressor removed.

Release screws (1) a few turns until holder (2) is loose. Do not remove holder (2).

Tightening torque: 12 31 3AZ .

Feed out alternator (3) and remove.

Fig 3: Identifying Screws, Bracket And Alternator

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.