Reply To: Oil leak on top or rubber sail drive bellows Dufour34P – Volvo Penta D1 -30

I had this on both my last boat and our 460….suspect it was gearbox venting as it go hot as never did find an actual source…. paper towels stuffed in the groove and changed very month or so was my final solution. It actually looked a lot worse than it was as you say it collects in the “groove” and neither the gearbox nor engine ever required topping up throughout the season