On Tue, 7 Dec 2004 14:44:15 -0500, "bob medico"
wrote:
I have a sailboat with a 1" stainless propellor shaft. The shaft is
supported outside by a rubber cutlass bearing in the hull (no strut). Inside
there is a short piece of hose with a stuffing box/ packing nut. When the
coupling is disconnected at the transmission the shaft will sag about 1/2".
My question is how do you know when the shaft coupling is at the correct
hieght (up and down) prior to getting out the feeler gauge etc. I imagine
this is a common question?

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It sounds to me like you may have a lot of play in the cutlass
bearing. Ideally a nice new snug cutlass will support the shaft
without a lot of movement. If there's any doubt I'd start by
replacing it since you've got things apart anyway.

If that solves the excessive play issue you're problem is solved. The
prop shaft should now point right at the transmission coupler. If
not, the engine needs to be raised/lowered as appropriate. If you
still have a lot of shaft play with a new cutlass you'll have to
average out the play left/right and top/bottom. Ideally the shaft
should point to the transmission when in the center of both ranges.

At that point you can mate up the flanges and start with the feeler
guages. Do you know if your shaft is straight? If not it might be a
good time to check before you get further into the process.