Well looking a bit further it appears that the big gear is designed to move a bit on the clutch casting, why would there be the rivets onto an outer steel sheet and not directly onto the gear? BUT my Haynes says somewhere that this should be tight! Also the gear rotation seems to 'land soft' as if there is some shock absorber in there, and does not 'clunk'.
I am not going to bash anything but refit it all as suggested, I only took it appart as it was very heavy and grabbing, ever since I changed the plates and springs a while ago.
Thanks for replies,
JohnR - 400-4 - GL1200A in Cold Old England.