Alternator: Service and Repair

12 31 020 Removing and installing or replacing alternator (N52, N52K, N51, N53)







IMPORTANT:
Aluminium magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released.
Aluminium screws/bolts are permitted with and without colour coding (blue).

For reliable identification:
Aluminium screws/bolts are not magnetic.
Jointing torque and angle of rotation must be observed without fail (risk of damage).







Necessary preliminary tasks:
- Turn off ignition
- Disconnect battery negative lead 61 20 900 Disconnecting and Connecting Battery Negative Lead
- Remove intake filter housing
- Remove alternator drive belt Service and Repair







Unlock plug (1) and remove.
Slacken nut (2).

Installation:
Tightening torque 12 31 1AZ.
Release screws and remove alternator (3).

Installation:
Replace aluminium screws.
Tightening torque 12 31 2AZ.