1973 38' Hatteras - Starboard transmission seized at end of season last year. Now removed and getting rebuilt. Think it had been dragging for quite a while. Now I am wondering about the Port transmission. It indicates no problem, but at about 3000 hours should I expect the same problem? For most of the life of these engines and transmissions the average speed has been about 8-10 knots only in the fresh water of Georgian Bay. Engines are 427 ci rated at 300 hp. They run really smooth after 3000 hours.
Is there some way to "flush" these transmissions, and is it recommended? What would I use for flushing fluid? Thanks.