As I recall
, the "engagement" portion of the gearing is the top of the cup shaped star gear and isnt much (perhaps 1/2") if the spring were weak or broken, or its bore filled with grease, that could be an issue with insufficient travel, as well as improper installation
of the cotter key. I believe the shaft has a boss the gear fits on, then a flat washer, and a small cotter key that must be installed flat in the base of the star gear to hold it all together. I would think SHORTENING the rod (remachine the step upwards, redrill cotter hole, and trim off end would be the process I think), but I would look for an obstruction inside the spindle keeping its travel limited first off, or a burr or something on the rod that is keeping it from traveling upwards. Its been a bit since I was inside one, but I am installing a few in a month, and will check if I recall
correctly. Also, is it possible an extra spacer washer is under the spindle, holding it up out of full engagement range?
I once had 2 lewmar
65's serviced by a "professional"immediately before departing. When I went to use them, neither spindle would turn. Upon dismantling and figuring out at sea, it turned out he had made a different mistake in each winch with spacers and gears. That was fun to diagnose without a diagram.....