hello before last season we had the drive off and had gimbal bearing replaced at a marina. figuring i would grease it at the end of the season (this was my first season with the boat) i did not catch the issues until after the first season and marina didnt say anything. the grease tube was corroded away and i believe thats how my bilge would fill up with water. at the end of the 2018 season i removed the drive again to see the brand new gimbal bearing was shot and i need a new one. completed rusted and doesnt spin. i noticed the corroded grease tube and im looking for help on how to fix this. im thinking remove the gimbal bearing and tap new threads for a grease fitting but as shown in photo 4 its very limited room. im also not trying to replace a gimbal bearing each season. how long would i non greased gimbal bearing last if i just plugged the hole because at least i need to water to stop entering the bilge and putting my outdrive and ujoints at risk. (which also need to be replaced) what are your guys recommendations? here are some photos.