I don't either...the little o-ring looked fine. When i first reassembled after removing and cleaning the bearing cover, I did not get any oil flow to the far end of the shaft...alot was leaking at the top of the bearing cover where it feeds into the shaft...I though I might be missing a part like an o-ring up there but didn't see anything on the fiche. So I blew out the shaft again, and with a long thin kabob type stick fed it all the way through to make sure there was no blockage.
Then i re-starte the bike (holding rubber stopper in which like to pop out as someone...pat?...noted), I was running at idle with some revving...no oil, till i tillted the bike to the right and a nice flow began and even with the bike straightup I got a constant dripping.
Can really bad oil develop blockages in small channels...cuz that's my guess...all the cleaning must have done something.
My old friction discs were rusting on the metal edges...I think that someone mentioned this was a sign of a lack of oil...well, i hope this fixes my shifting problem...if not, I'm SOL...k, thx.