Separating a shaft from the gearbox clamp

[Norman_E]

Thanks to all, I'll be pursuing the bolts through the flange route this weekend. One last little related question - do they go back in easier than they come out because I don't see a route for pulling them back in?

Unless you can open the slits in the coupling a bit, the shaft can be very hard to get back in. If there is a keyway you cannot even help it in by twisting it. Unless you can use forcing screws to open it up a bit, remove the coupling once the shaft is out, and take it to a workshop where any rust on the inner surface can be removed and forcing screws fitted. Then try it on the shaft outside the boat to ensure that it can be pushed on with hand pressure, before re-fitting it. The clamp screws will hold it tight once fitted.

If it has a keyway, you should check that the key fits without any sideways play in either shaft or coupling, but it must not under any circumstances be tight in the up and down direction. I have seen keyed shafts get jammed almost immoveably because the keyway in one or other component was of tapering depth, resulting in the key jamming once an attempt to withdraw the shaft slid the key up the taper to the point where it stuck.