FXD Shocks won't adjust
 

This is a 2005 Dyna FXD.
I have the proper spaner but the shock adjustment ring will not turn.
Any ideas?

If you havn't already tried it jack up the bike so rear tire is off the ground.

I know this stupid but I had the same problem even with the correct spanner. The shocks were already at their max up or down. I cant remember. Try reversing your direction.

Spray some teflon based lube(Tri Flow for instance) on the bottom adjustment ring,let soak a couple of minutes.Turn both adjuster rings to the lowest position,spray again,adjust each shock to the next higher position until you reach the desired level of preload.