Hmm 'Looks like Hardinge have changed the gear and the apron cover bearing to suit; Mine, like yours, has a small (5/8"?) apron cover bearing.



The clutches come apart and reassemble easily; there is enough thread on the centre nut to be able to start it with a light push.

It's well worth taking them apart just to check them, and it will allow you to make sure the threading/power feed interlock bar (which slides in a slot in the apron cover under the clutches) is free to move (it is spring loaded towards the threading lever so, if it sticks, the power feed lever will not move after you've closed/openned the half-nuts)