Fan clutch - what i do is leave the serp belt in place. And I used a Large cresent wrench and a hammer. make sure you have the right direction as the motor spin in the direction to tighten the nut. For me it was Right to Left. Place the wrench and 2-3 deliberate blows broke loose. Depends on how long the clutch has been there how easy this would work. I also used the pro $180 tool which is the same thing as my cresent but the hammer is an air hammer...works like a champ but too expensive for me.

hope this helps.

-Bob