Re: Hurth engagement question
Do be careful of relieving the pressure on that seal.. it's often the 'push' from the coupling position that maintains the pressure. If the bellows can 'push your prop shaft' inboard that will end up releasing some of the seal pressure. Perhaps more of an issue with a strut/shaft than a prop in an aperture like you have.
When we pulled our gear with a PSS seal as a precaution I heavily taped the collar to the seal just in case things 'slipped'....
To see if the actuating cam is worn down as I described it's simply release the control cable, undo 4 bolts that hold the plate on and the lever and the internal cam come out clean.. though I suppose your access may not be that great with the engine deepish in the bilge.
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"