I have a F-4330 finshier for a 6230. The bin that holds the paper for stapling does not lower to the correct position to get stapled.

Try this- open up the Middle Tray Clutch(the one at the top rear side of the Intermediate Section). There will be two black plastic shims inside, lone on each side of the body. Remove one, it doesn't matter which one. Make sure the clutch is clean and reinstall it. If this doesn't work, try replacing the clutch with a new one, but you still may have to remove one of the shims. Good luck!

Are you are referring to the elevator that lifts the paper up and out of the middle tray? Is it coming around the bottom of the middle tray and not stopping soon enough? If what bazookajoe recommended doesn’t work, try folding a piece of paper and wedging it between the top shaft (the one the green knob attaches to) and the black plastic of the middle tray to add a little resistance and act as a break.