Thanks Supradupe for your reply... I start the job tomorrow: ML 320 2002
With a lot of negative ... attitude Why? the " automatic tensioner pulley " or " automatic adjusting tensioner " huge problems - I replaced a new belt last water pump as it shreaded but did I battle!!!!!!

1)These posts help! thanks! but I am a bit slow ...

http://www.peachparts.com/shopforum/showthread.php?t=103418&highlight=serpentine+belt

To remove the belt you need to release the tensioner, to do this attach a torx e10 socket and ratchet to the pully on the tensioner and pull just as if you were loosening up a bolt. There is a hole on the tensioner to hold it in place with a metal rod, I never saw it so I simply slipped the belt off at this point and let the tensioner back out. then slip the belt off toss it and put on the new belt. The tensioner is self tensioning so just let it go and its ready to run. Check to make sure the belt is seated on all the pullys correctly

Question:
A
1) Is this torx bolt on the back of the tensioner pulley (ML 320 2002)? or on the back of the tensioner housing?

2) Can one use a 12" ratchet or a longer breaker bar (or either) with the torx e10 socket?

3) Which direction must one turn or pull the ratchet or breaker bar to release the - Left, Right (while facing the motor)?

4) What degree is the maximum one can turn or pull the ratchet or breaker bar to release ?

5) I think there are casting knobs on the back of the tensioner housing - How does one HOLD the tensioner in place? - long bar, short bar, would the bar run between these knobs and rest against what? or would one shove the bar perpendicular to the knobs?

6) Maybe even a pic of the torx e10 socket in place where it goes on the pulley would be nice?

B
Is there another way of loosening the "viscous fan or clutch fan" if one does NOT have the special tool to hold the fan still or steady while undoing the large nut with a flat wrench or spanner?

Thank you