Boat is a 1975 Sea Ray SRV 190 with a Mercruiser 233. The steering cable is original and over the winter it seized up. I have disconnected all of it except for the coupler nut on the cable guide at the transom. That nut is frozen solid. i.e, I lock the cable guide as tight as I can with the adjusting nuts and apply torque to the coupling nut, maybe about 75 ft-lb, the cable guide loosens up and the coupler nut is still tight. There just seems to be no way to get these guys apart short of ruining the cable guide with a pipe wrench or using heat. Anybody ever had to deal with this? My last resort is to apply heat to the coupler nut in a confined fiberglass cavity with oily surfaces around. I'm worried about fire. I have a copy of service manual 2. A good picture of the mechanics is shown in Fig. 1 on Page 2A-8. I need advice from someone who has solved this problem. Tnx.