Ive noticed gear oil leaking out of my rear swingarm boot(1990 R100GSPD) and suspect it is coming upstream from my output shaft-seal or vent hole(a little evidence present at seal driveshaft coupling). I went on a 1000mile ride this weekend and about 20cc worth pooled down into the rear lower boot. no noticeable loss of capacity in my final drive or gearbox. Would a new outputshaft seal remedy this? 40,000 miles. Any help greatly appreciated!!