My last boat was a Weldcraft Renegade with an American Turbine SD 309 pump. Every year around September my steering would start getting tight. I had it in the ocean every year as well. It was not the steering rod either becase when I took it of the pump, the steering wheel would turn just as easy as the day I bought it brand new.
I took the nozzle apart and cleaned the steering pins with a water resistant solvent, changed out the brass bushings and then put everything back together. The end result was smooth and easy steering. Just remember to use lock tight on your bolts that assemble the nozzle. Two years ago I didn't do that and the end result was a bolt coming out while I was 12 miles away from the dock. The lower steering pin dropped out and I had no reverse or steering at all
Thanks for the tow Dipnet