Gogarty wrote:

Many thanks. The unit is remarkably accessible unlike most things in a
sailboat engine room. My main concern is those corroded fasteners on the
flange between the prop shaft and tranny. They have been bathed in salt
water stuffing box drip -- sometimes more than a drip -- for years. Before I
break anything, is there a really. really good loosener upper for corroded
fasteners?

You can buy penetrating oil at most auto parts
stores. There are various brands that various
people swear by. Personally, I haven't had much
luck with penetrating oil, but it may be that I'm
just not patient enough, or haven't found the
right brand yet.

For the shaft flange, a little heat from a propane
torch on the nuts will probably get them loose if
penetrating oil doesn't. Just be careful not to
set anything on fire! Also, if you break one of
those bolts, they are easy to replace, and you
should probably replace them with new bolts anyway.

The bolts I would worry about are the ones that
hold the transmission housing to the engine block,
because if you break one of them it will have to
be drilled out.

Don W.