Alternator: Service and Repair

Removing And Installing Or Replacing Alternator (M52, M52TU, S50US, S52, M54)

Read out fault memories of control units. Turn off ignition.
Follow instructions for disconnecting and connecting battery.
Instructions For Disconnecting and Connecting Battery
Disconnect and cover battery negative terminal.

Remove intake filter housing.
Remove fan clutch.
Remove alternator drive belt. Service and Repair
Remove supply tank for power steering pump with bracket and place to one side.

If necessary, drain supply tank for power steering pump, remove with holder and place to one side.

NOTE: Lines on supply tank for power steering pump remain connected.







If fitted:
Disconnect air hose.







Version 1

Take off cap on connections
Disconnect plug connection (1).
Release nut (2) and remove battery positive lead.

Tighten torqure:

- Terminal D+ M10 / M20 5Nm
- All others M6 7Nm
- Terminal B+ S38 / B38 8Nm
- All others M8 13Nm





Version 2

Unlock and detach plug connection (1).
Release nut (2) and disconnect battery positive lead.


- Terminal D+ M10 / M20 5Nm
- All others M6 7Nm
- Terminal B+ S38 / B38 8Nm
- All others M8 13Nm





Version without idler pulley:
Release alternator screws in succession
while simultaneously gripping alternator firmly.
Remove altenator

Version with idler pulley:
Remove cover from idler pulley (1).
Release screw and remove idler pulley(1).
Release screw and remove alternator (2).






Version with idler pulley

Installtaion:
Turn lock of tensioning roller must engage in alternator groove.





Note:Interrogate fault memory of DME control unit.
Now clear the fault memory.