06 YZ450F- I noticed after my last ride that there was a silver dollar section on the top of the case that was wet with oil. I cleaned it off, checked the oil, and kept riding. less than hour later it was right back. I looked for any cracks in the case but the oil appears to be coming from the clutch push lever. Has anyone else had this problem? I am planning to remove the shaft for inspection and to replace the bearing/seal. Any other thought on what may be causing this?