If you don't have any luck adjusting the lever, here is a video on how to remove the PTO clutch.
http://www.youtube.com/watch?v=jUol4R9nYAw
Here is the exploded parts sheet
http://www.partstree.com/parts/?lc=c...&dn=0011200014
There is a service kit (Cub Cadet 759-3490, $68) that can be ordered that contains a replacement disc, center spring and the 3 alignment springs. You probably will need a throwout bearing too.
I'm currently fighting this same battle with my 104 and have it re-assembled, trying to get adjusted. See posts. Good luck.