Re: Water in Oil 1957 Johnson AD-11 7.5HP

[Don]

Well, to be honest, these "clam shell" type gearcases are a challenge to get sealed properly….Trying to pull those seals out can be tricky as well, it is very easy to damage the castings the seals are in. You will need a special tool for removing the shift rod bushing to access the shift rod oring.
I would watch all the videos posted, then gather up the tools you will need and ask questions…
The best way to start this project is to figure out where the leaks are before ripping the gearcase apart. Simply replacing seals and orings does not guarantee the case will seal properly, there might be casting flaws, or grooves in the shafts. The best procedure is to pressure test the gearcase once it is removed from the exhaust housing. While pressurized at about 5PSI, submerging it into a bucket of water while rotating that shafts, and moving the shift rod will help isolate problem areas….