DGC,
To be honest, I'm not sure. Not exactly a reel mechanic and I've never looked inside a medalist until now. The symptom is that the reel slips, like it misses maybe 1 out of every 3 clicks, both on reeling and when the drag is going. The sound is very noticable, but you can tell by feel as well when your reeling. Kind of a catch, slip, catch, slip.
I had it out last night to look at it, but I haven't got much time to really look up any parts lists or anything. On the back of the spool, there is a spring loaded little metal post sticking out, that appears would interact with the ratchet.
I don't have a "good" metal post to compare against, but it looks to me as if mine is badly chipped and mishapen. It also spins freely. If you push it in, it tends to stick inside because the chipped part is catching on the lip. Pretty sure this is my problem. I can take a picture this evening if that would help.
Hadn't yet gotten around to lookin for parts, but maybe you can save me some time and tell me what I need to get?