Re: '67 johnson 100 hp v4tl13
My concern here would be that the grease may cause the the gear hub, and gear spring to slip. My exsperience has been that once they slip, they will no longer hold. That gearcase has two electro magnets for forward, and reverse. The magnet attracts a spring that is wound in square section, and wrap's around the hub of the gear. The more force put on the gear, the tighter it grips. I have never had to deal with a problem like this, so this is just a suggestion. I would fill the gearcase with kerosene, or fuel oil. Run the engine on a hose in neutral, think of a 100 HP blender here. The mixture here should then run out. You may have to do this a couple of times depending on what the mixture looks like. I know that kerosene, or fuel oil would make a poor lubricant, but you are putting no strain on the gear train, or bearings. Looking at you engine from the back, and on the left side of the gearcase. Above the cavitation plate ther is an oblong plate about 2-1/2 inch's long, and about an inch wide. Use this plate as a template, and cut out a piece just like it out of sheet metal. Drill a 1/2 in. hole in the center, and soft solder on a female garden hose connector. I have made several of these over the year's, and it work's very well. Hopefully! some of the other guy's may have other suggestions. The oil to use is type C gear oil.