Fan or alternator removal - ML-270

[Mark A]

I got all of the parts to change the pulley on the alternator of my ML-270CDI last night. Unfortunately there isn't enough clearance to get the removal tool in past the fax housing. I tried to remove the alternator, but can't find the other bolts (I suspect that they are behing the bracket holding the turbocharger). I undid the bolts and slipped the fan out of the hooks, but still can't get fan far enough out of the way to remove the pulley.

I was going to remove the electrics and drop the fan right out of the way, but am a bit concerned following the last post about the car locking system not working properly following a battery disconnection.

Help !!!!!

Mark

 

[Captain Flack]

I replaced the same on my C270(even less space) and simply took out the fan. There is a connection at the bottom of the radiator which unplugs and the fan can almost just be lifted out of the way. I also had to disconnect a water pipe at the top of the radiator to allow the fan to be lifted out, but there may be enough room on the ML. The alternator is water cooled so I did not want to remove it, but it is actually easier to leave it in situe as the pulley is bl**dy tight.

 

[BlackC55]

The ML is less sensitive to voltage changes but be careful still.

There is no need really to disconnect the battery.

 

[Mark A]

Thanks once again Black.

I had a look at removing the alternator last night, but don't want to do that as it is a water cooled one (WTF is that about !!!).

I will drop the fan out and just be careful of the electrics.

Cheers, Mark

 

[television]

Thanks once again Black.

I had a look at removing the alternator last night, but don't want to do that as it is a water cooled one (WTF is that about !!!).

I will drop the fan out and just be careful of the electrics.

Cheers, Mark

These alternators are water cooled as there is insufficient surface area for adequate cooling for the diodes in the regulator. So water is used to take away the heat.

 

[BlackC55]

These alternators are water cooled as there is insufficient surface area for adequate cooling for the diodes in the regulator. So water is used to take away the heat.

And is is also use to warm the engine up faster as the cdi units are very thermal efficient.

 

[television]

And is is also use to warm the engine up faster as the cdi units are very thermal efficient.

That makes sense after a start the alternator is working at max for a while, clever really

 

[Mark A]

Good idea, but I would have thought that a pipe in and a pipe out would be better than a single pipe. I am used to working on cars a bit, but have never seen a water cooled alternator or a clutch mechanism for an alternator pulley before.

Every day is an adventure with an MB.

Cheers guys, Mark

 

[BlackC55]

Those pulleys are called Over Running Alternator Pulleys (OAPs)

The OAP has a one way clutch that enguages when accelerating and disenguages during deceleration of the engine speed, allowing the alternator to freewheel.

It is there to absorb vibrations and fluctuations in the belt drive system due to larger belts and bigger alternators being fitted.

Failure of the OAP can mean the belt flaps and wears premeturely and can increase the load on the alternator bushes and bearings.