I started noticing oil inside my rear wheel. Specifically, I started noticing it after the day I dumped the clutch and spun the rear wheel for the first time (the one from the post where I was riding with a friend on his R1). Anyway, it is apparently coming from between the rear hub. I have recently (as in a couple weeks and 1000 miles ago) I changed the rear end oil to Mobil 1 Synthetic 70W90. Does this mean my seal has gone out? Is this a big deal? Let me know if I should be concerned. I have been wiping up the spray in the wheel and around the hub, but after a long ride, dirt shows that there is still a leak. Looked like I needed to tighten the drain plug the first time I noticed it, so I figured it was coming from the plug and then getting spun around the hub when it dripped down there. This last time though, there was no evidence of drain around the plug, yet I show evidence of oil around the hub as well as in the wheel.