Ouch. Our cutless bearing failed to be cutless. It cut into the drive shaft.
The bearing (on the outside) is designed to dribble cooling water into a shaft seal (or "stuffing gland" or "stuffing box") on the inside. The shaft seal includes a wrapping with flax under a little bit of compression and a slow drip of water keeps things cool.
As long as we're replacing the entire 5' × 1¼" steel drive shaft and the cutless bearing, we may as well replace the shaft seal on the inside, also. The Tides Marine Sure Seal looks like just the ticket for a long, safe shaft and bearing life. No more flax.
We can have the propellor resurfaced and spin balanced (why not? It's off anyway.)
The only thing that's left to be done on the drive train would be to replace the engine mounts in case it needs realignment.
Turns out, the alignment is perfect. (Whew! One less thing to replace.)
We started out with "plug a hole", "wax" and "paint". Seriously. That was the plan: two days of work by the boatyard more or less.
Once we saw the bottom, paint was not interesting any more, since last year's paint was looking spiffy.
So, as long as she's out of the water we may as well look at the slightly wobbly cutless bearing. That—as we've seen—turned into bearing, shaft, seals (and possibly more.) Yes, a quick spring haul-out changed into a major project.
Maybe we should have left well-enough alone?
The answer no, leaving well-enough alone isn't an option. There's a small possibility that a scored shaft can crack or even break. If it drops off, that would then leave a large hole in the back of the boat that can be difficult to plug because of the mortal remains of the shaft being in the way of any sensible temporary plug. Unlike a failed hose on a through-hull, you can't just take a utility knife to it and make a clean, pluggable hole. We own a large number of wooden and plastic TruPlug plugs just in case.