Ron, 10mm above the nut is about half a way the adjusting range. It means you still have a few turns of adjustment in both boxes.
A good idea would be to overhaul the spare box you have with
a kit they sell for the purpose (I just overhauled a spare one) and I know you are more than up to the job. There is a superb step-by-step write up a fellow member made
(David Petryk) with pics and process stages.