docc is probably correct, pressed in. Never heard, seen a leak there before. Everything else seems A1 cleaned. You need to take the cover of, if the bike doesn't have the Chuck unbreakeable shift spring. Note some different lenght bolts. When putting back the cover, it's easy to hear it's all in, clack. Not much pressure in there, oil level correct ? Silicone, JB W. as proposed.
Cheers Tom.