Same issue
We have the same issue (also on our 1988 Catalina 30 MKII). I know that the stiffness in our case is due to excessive friction between the rudder post and the fiberglass tube in which it rotates. This is most-likely due to the previous owner using some type of grease which hardened over time (becoming tar-like).We've been through the drill of adjusting, lubing, etc. all the cables and sheeves. There was an outstanding article in a recent issue of Mainsheet in which exactly this kind of problem was solved by removing the rudder, cleaning the tube with a wire brush, and reinserting the rudder. You can contact me by e-mail if you need more info. (I'm in the owner's directory). It's probably not an expensive fix because the steering mechanism is pretty simple with only a few possible points of friction.Gary KunkelCatalina 30 "Folie a Deux"Channel Islands Harbor, CA