I believe 1996-1997 M104 engines require a wrench to counter-hold the fan clutch during removal. This is different from the bent 1/4" steel tool that was improvised for earlier models. A prior thread, http://www.peachparts.com/shopforum/showthread.php?t=51248, identifies the wrench as a flat 64mm wrench and goes on to incorrectly identify a source for the tool (the incorrect reference is to the earlier version of the tool). The W124 CD identifies the tool as counter holder 120 589 02 01 00. Does anyone know of an alternate source for this tool or an alternate procedure to counter-hold the viscous fan?