Sooooo, after a long rainy ride a few weeks ago I thought I'd check my final drive oil as my breather has managed to let water in before. Sure enough it was milky and gross. I drained it but am now left wondering: most people say they only change their final drive / tranny / driveshaft oil every 10,000 miles yet mine gets water in it any time I cross a stream or ride in the rain for hours on end. Do most just accept this and allow it to cook out the next time you ride or what? I don't feel like changing all my gear oil weekly. Anybody care to just tell me it's OK?