Sorry, can"t help ypu on your problem... Never heard of farendloose drum mower. Could you post pictures... I"d like to see... Think your mower may be a completely different animal compared to mine.
I have a MINOSagri 190, and the back side of the belts started rubbing the cover over the drive pulley. Had to move the whole shroud assy as far to the right as I could to avoid contact with back of belts.