Hi,

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?

TIA

Bob

bob medico wrote:
Hi,

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?

TIA

Bob


Well, believe it or not, you can get quite close by sight and touch.

Regardless, you would need to move the engine, not the shaft. Or
don't allow the adjustment to move when you take it out. Whenever I
remove my engine, I unscrew the lag bolts holding the adjustable
mounts to the beds. Putting it back in requires no adjustment.

I have a similar sounding packing tube arrangement.

Terry K

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?

===================================

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.

In article ,
says...
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".

Bob, I'm not totally sure you have a problem.

When disconnected from the engine/transmission, the shaft is supported
on two ends, one by the rubber 'Cutlass' bearing, and the other by a
(variably flexible) rubber 'hose' section to the "stuffing box'. Some
rubber hose sections are quite short and of rigid material, and the
shaft seems to hold position when disconnected. Others are more flexible
and 'sag' more.

The Cutlass bearings rarely wear out badly. I have one with 25 years and
thousands of hours on it. It probably has .025 sideplay but doesn't
complain. And that's a V8 powerboat running 2500 rpm, not a sailboat.

Grab the coupling on the shaft. Put a moderate amount of force on it
(say 5 pounds) in each of the up, down and sideways directions. How much
does it move? Is there a 'hard stop' feeling in each direction (may be
the shaft touching the inside of the "Shaft Log" or hull tube). If it
moves quite a bit, try to measure where the center of it's travel is.
Does that point right at the engine coupling?

There are two separate issues he

(1) Overall positional alignment of the engine coupling centerline with
the shaft centerline (In it's "center" position, whatever that is).

(2) The Angular alignment between the two couplings.

You must bring the two couplings together and THEN use "feeler gauges"
to determine if their angular alignment is right. "Right" means "they
meet squarely." If they meet squarely, the gap between the two coupling
halves will be zero (you can't get a thin ( maybe .002 in) shim in
anywhere around the periphery, or the SAME (You can put a feeler gauge
of (say .020) in all the way around and it is equally tight.

Settle the positional alignment issue first. Then check the angular
alignment.

Unless something drastic happened like worn or broken motor mounts, it's
unlikely that the positional alignment "went off" by 1/2" Thats a lot.

If that "rubber hose" section feels spongy at all, better replace it!
Greasing the stuffing box eventually deteriorates the rubber. You REALLY
don't want that hose section to fail!

Let us know if this makes sense, and what you see on your particular
boat and engine setup. I'd like to hear what you find out and finally
do!

(I'm current BoatLess In Africa and looking for an oldster to work
on...)

--
Regards, Terry King ...On the Mediterranean in Carthage

Thanks for your comments. I have already sent both shaft and coupling out to
machine shop to check straightness. I also plan to replace the rubber hose
that the packing nut attaches to. When I get those back in I'll let you know
how things turn out.

Bob

"bob medico" wrote in message
...
Hi,

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?

TIA

Bob

"Terry King" wrote in message
.. .
In article ,
says...
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".

Bob, I'm not totally sure you have a problem.

When disconnected from the engine/transmission, the shaft is supported
on two ends, one by the rubber 'Cutlass' bearing, and the other by a
(variably flexible) rubber 'hose' section to the "stuffing box'. Some
rubber hose sections are quite short and of rigid material, and the
shaft seems to hold position when disconnected. Others are more flexible
and 'sag' more.

The Cutlass bearings rarely wear out badly. I have one with 25 years and
thousands of hours on it. It probably has .025 sideplay but doesn't
complain. And that's a V8 powerboat running 2500 rpm, not a sailboat.

Grab the coupling on the shaft. Put a moderate amount of force on it
(say 5 pounds) in each of the up, down and sideways directions. How much
does it move? Is there a 'hard stop' feeling in each direction (may be
the shaft touching the inside of the "Shaft Log" or hull tube). If it
moves quite a bit, try to measure where the center of it's travel is.
Does that point right at the engine coupling?

There are two separate issues he

(1) Overall positional alignment of the engine coupling centerline with
the shaft centerline (In it's "center" position, whatever that is).

If the set up has run with the positioinal alignment out for any length of
time, there will be wear in the cutless bearing in opposite positions end to
end. With the shaft out you could look in and see this.

(2) The Angular alignment between the two couplings.

You must bring the two couplings together and THEN use "feeler gauges"
to determine if their angular alignment is right. "Right" means "they
meet squarely." If they meet squarely, the gap between the two coupling
halves will be zero (you can't get a thin ( maybe .002 in) shim in
anywhere around the periphery, or the SAME (You can put a feeler gauge
of (say .020) in all the way around and it is equally tight.

Settle the positional alignment issue first. Then check the angular
alignment.

Unless something drastic happened like worn or broken motor mounts, it's
unlikely that the positional alignment "went off" by 1/2" Thats a lot.

If that "rubber hose" section feels spongy at all, better replace it!
Greasing the stuffing box eventually deteriorates the rubber. You REALLY
don't want that hose section to fail!

Let us know if this makes sense, and what you see on your particular
boat and engine setup. I'd like to hear what you find out and finally
do!

(I'm current BoatLess In Africa and looking for an oldster to work
on...)

--
Regards, Terry King ...On the Mediterranean in Carthage

On Tue, 07 Dec 2004 22:33:22 +0100, Terry King wrote:

In article ,
says...
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".

Bob, I'm not totally sure you have a problem.

When disconnected from the engine/transmission, the shaft is supported
on two ends, one by the rubber 'Cutlass' bearing, and the other by a
(variably flexible) rubber 'hose' section to the "stuffing box'. Some
rubber hose sections are quite short and of rigid material, and the
shaft seems to hold position when disconnected. Others are more flexible
and 'sag' more.

The Cutlass bearings rarely wear out badly. I have one with 25 years and
thousands of hours on it. It probably has .025 sideplay but doesn't
complain. And that's a V8 powerboat running 2500 rpm, not a sailboat.

Grab the coupling on the shaft. Put a moderate amount of force on it
(say 5 pounds) in each of the up, down and sideways directions. How much
does it move? Is there a 'hard stop' feeling in each direction (may be
the shaft touching the inside of the "Shaft Log" or hull tube). If it
moves quite a bit, try to measure where the center of it's travel is.
Does that point right at the engine coupling?

There are two separate issues he

(1) Overall positional alignment of the engine coupling centerline with
the shaft centerline (In it's "center" position, whatever that is).

(2) The Angular alignment between the two couplings.

You must bring the two couplings together and THEN use "feeler gauges"
to determine if their angular alignment is right. "Right" means "they
meet squarely." If they meet squarely, the gap between the two coupling
halves will be zero (you can't get a thin ( maybe .002 in) shim in
anywhere around the periphery, or the SAME (You can put a feeler gauge
of (say .020) in all the way around and it is equally tight.

Settle the positional alignment issue first. Then check the angular
alignment.

Unless something drastic happened like worn or broken motor mounts, it's
unlikely that the positional alignment "went off" by 1/2" Thats a lot.

If that "rubber hose" section feels spongy at all, better replace it!
Greasing the stuffing box eventually deteriorates the rubber. You REALLY
don't want that hose section to fail!

Let us know if this makes sense, and what you see on your particular
boat and engine setup. I'd like to hear what you find out and finally
do!

(I'm current BoatLess In Africa and looking for an oldster to work
on...)

That was really an informative post. The OP should definitely refer back
to it when he is mating the transmission to the shaft.

I just want to mention that a cutlass bearing can get worn out if the
shaft gets bent for some reason, or if the prop is spun while the boat is
dry. I bent a shaft after fouling the prop on a cargo net. It wasn't so
bent that it caused a lot of vibration or anything, but it did wear the
bearing a bit.

--Mac

"bob medico" wrote in message
...
Thanks for your comments. I have already sent both shaft and coupling out
to
machine shop to check straightness. I also plan to replace the rubber hose
that the packing nut attaches to. When I get those back in I'll let you
know
how things turn out.
............................. and originally
...............................
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
height (up and down) prior to getting out the feeler gauge etc. I
imagine
this is a common question?

Bob thanks for raising your question.
We have similar problem on a Westerly 26 with Volvo MD-1B. Our stuffing
box/cutlass bearing tube sound identical.
We think our problem is damaged engine mounts? We got a rope around the prop
and that broke the rubber shaft couplings! We remade the cutlass bearing
mounting. Installed a new shaft and replaced the couplings.
But every time I bolt up the shaft coupling it moves it moves eccentrically
when the shaft it rotated by hand; rebolting at 90 or 180 degrees does not
help. Only thing seems to be engine is out of line with shaft due to the
damaged engine mounts?????
Would be most interested if you could post your outcome.
Best of luck. Terry.

That looks a lot like a bent shaft. Sorry for the bad news.
Jacques from bateau.com