Reverse gear switch leaks / transmission oil loss!

Hey people I have a big problem and I hope you can help me with that… and that.. I built in a new gearbox on Wednesday, because my old corrosive noises made everything nice and good, everything worked out wonderfully, just jettison to my problem… the reverse gear switch (which is square, so not the round) is leaking in my eyes, because it constantly drips out. just like the simmerring for the drive shaft left (driver side), the spot is also always bit wet, even though it’s been renewed… can you give me some tips on how to best seal all this, not that I have to make my farm new in 2 weeks because of all the oil stains? hope you can help me