Twice recently I have had a problem with the gearshift on my elderly (1978) Yanmar diesel (2 cylinder, 15 hp). The shift has jammed in forward gear and the remote control ( a new Teleflex single lever) has been unable to shift it. The throttle part of things works fine when the motor is not in gear but is totally stuck when I put it into gear.
I have unjammed it by pulling and pushing on the short stubby lever which is on the transmission, but I am concerned that this will happen again at the wrong time.
Is it likely to be a lubrication problem ? The remote is very clean and well greased, the cables are quite new, but the stubby lever is the original and is rather close to the bilge water. Does that need a big load of grease?

Thanks for any advice

Richard Isherwood
Port Townsend WA