I agree about looking for
the most obvious causes of steering problems first. I had a similar problem with my H28.5 and none of the easy things were the cause. Not sure how your steering configuration compares to mine, but when my boat was hauled last winter I was surprised to find no evidence of a lower bearing in the rudder tube. Perhaps more importantly, the upper Derlin (or whatever they are made from) bearings were worn out. The bearing holes through which the rudder stock passes, and is then connected to the steering quadrants, were elongated from wear and age. The result was that I had a very "tight spot" when turning the wheel all the way to starboard as the rudder stock was rubbing against the inside of the rudder tube. Not a good thing. I had new upper and lower bearings fabricated over the winter and now my steering is as smooth and precise as that of a new sports car. Everything wears out....