Alternator: Service and Repair

Removing and installing 3-phase alternator (M20, M 21, M 30, M 40, S 38)




Disconnect negative terminal from battery. (Or pos. terminal on the firewall).

Note: M 21/M 30 battery under rear bench seat on right.





M 20 / Remove air filter with volume air flow sensor.

Remove plug, loosen hose clip, unfasten retaining screws, lift up air filter with volume air flow sensor, unfasten retaining screws from coolant hose and lift out air filter together with volume air flow sensor.




Remove coolant air hose.

Loosen hose clamps.

Note: M 30 / Remove coolant hose prior to disassembly.




Alternator: remove protective cover.




Alternator:
Unfasten leads on connection B+ (term. 30) and D+ (term. 61).




Loosen upper nut and remove screw together with tensioning wheel.

Loosen lower nut and remove screw (leads D+/B+ removed)

Installation:
Tightening Torque = D+ (7 Nm) / B+ (13 Nm)




Installation instruction:
Tensioning V-belt (SR version) see1231299.