Ken,
The clutch on my 300 that I'm in the process of finishing had a shim also. I found that the bearing, which was toast, was loose both in between the 2 snap rings and was also not a press fit anymore in the housing. I took the shim out and put my "emergency bearing" in with lock tite bearing retainer. Made sure the 2 snap rings were put in with the bow inward and it works great. Eventually I will have to replace it, but for now it works ok.
BTW, the "emergency bearing" was one I replaced from my 314. Really didn't need it but did it anyway. Also the bow I refer to is when you take these snap rings out they sometimes are no longer flat. Should really have replaced them.
Bob