[Spam] RE: [Amel Yacht Owners] Re: SM2000 Bow thruster service


eric freedman
 

Hi,

I believe the thruster takes .3 liters of 90 weight gear oil.

Fair winds

Eric sm 376 kimberlite



_____

From: amelyachtowners@yahoogroups.com
[mailto:amelyachtowners@yahoogroups.com] On Behalf Of Judy
Sent: Tuesday, May 01, 2007 7:44 AM
To: amelyachtowners@yahoogroups.com
Subject: [Amel Yacht Owners] Re: SM2000 Bow thruster service



Mike,

Let me try to help you with your questions. I did not design the bow
thruster, nor am I an engineer. I certainly cannot suggest intended
strategies, but I have some suggestions for you. I have used and
serviced it successfully and may be of some help.

1) The penetration through the hull is above the water line when at rest
in calm water.

2 a) The 2 closed cell foam rings on the shaft outside the hull are
compressed against the hull opening when the bow thruster is fully up
and the safety pin is in place.It is important to pull on the wire
bringing the thruster high enough to insert the pin each time you go
sailing (you will also have to turn OFF the power switch which is in the
path of inserting the pin).

2b) On the Bow Thruster shaft there are 2 closed cell foam rings outside
the hull which are compressed when the thruster is in full up and the
pin is inserted.my experience is if you do not insert the pin, you
will get a small amount of water in the forward bilge when sailing.
There is one closed cell foam ring inside the hull compressed when the
thruster motor is in the full down position.

2c) There is an oil seal just behind the propeller and this oil seal
probably needs replacing on your boat.

3a). The 2 foam rings outside the hull should be adhered to the foot of
the shaft and the gear box and ride up and down with the shaft.

3b) If the surface of the bow thruster well is oily it most likely is
because the seal behind the propeller needs replacing. A bad seal will
cause water to penetrate and water penetrating the thruster will cause
the oil to rise and possibly overflow when running.

3c) You should have fare access to this area to clean when the thruster
is removed.

4) I am not sure about the 2 grooves in the sleeved penetration in the
hull.

5) There should be one closed cell foam ring inside the hull compressed
when the thruster motor is in the full down position.

6) There is an oil seal behind the propeller. It keeps sea water out
and also keeps oil inside the thruster. This oil seal is pressed into
the gear housing, and should be replaced when you service the unit. The
flat side of the seal faces the sea water and propeller. You may want
to use a little RTV (room temperature vulcanizing) silicone sealant to
help ensure that it stays in place and seals completely. I suggest that
when draining the thruster that you capture the oil in a transparent
container to see if there is any water in it. If there is, change the
seal behind the propeller.

7) My guess is that the water you had in your forward bilges was caused
by not pulling the wire and inserting the pin while under sail.

8) I assume that you filled the thruster to the same level that it had
when you removed it. If so, it was overfilled as it should definitely
not take that much oil.
Best,

Bill & Judy Rouse
s/v BeBe anchored at Bequia, The Genadines
SM2 #387

--- In amelyachtowners@ <mailto:amelyachtowners%40yahoogroups.com>
yahoogroups.com, "Mike Ondra" <mondra@...> wrote:

We just completed servicing Aletes' bow thruster on the hard,
postings from this BB in our greasy hands. Yet upon completion we
have concerns about the water tight integrity of the bow thruster.

1. Fundamentally, is the penetration through the hull above or below
the water line when at rest in calm water? It appeared to us that it
was slightly below the water line, which conflicts with the concept
of dropping out the propeller/shaft assembly while in the water and
raises images of the boat with water where it should not be.

2. What is the seal strategy of the assembly? We found only the 2
closed cell foam rings on the shaft outside the hull that are
compressed against the hull opening when the bow thruster is fully
up. Other postings refer to up to 5 seals: 1 just behind the
propeller, the 2 we have around the shaft just outside the hull, 1 at
the hull opening, and 1 foam ring above the opening that would be
compressed when the truster motor is in the full down position.

3. The 2 foam rings outside the hull were adhered to the foot of the
shaft and the gear box and rode up and down with the shaft. It would
seem that if they were adhered to the bottom of the opening in the
hull they would seal to the shaft as well as be compressed when the
assembly was full up. However the friction of the shaft moving up and
down could wear the seal and/or pull the rings away from the
adhesive. Also that surface up in the bow thruster well is oily
(difficult to adhere to) and not very accessible for cleaning up
adhesive in preparation for a new seal.

4. The sleeved penetration in the hull, about 2" tall, had 2 grooves
in it. Is this or are there other provisions for a seal at this
location that would not move with the assembly and seal to the shaft?

5. We did not find any seals on the top side of the hull. Should
there be a foam ring on top to seal when the motor is down?

6. Is there a seal required behind the propeller and what does it
look like and do? The propeller shaft has a seal pressed into the
gear housing, and should that be replacable?

7. Again, what is the total seal strategy? Although we have had only
a very minor amount of water in our forward bilges, what we found
seemed to be profoundly not leak proof.

8. Our shaft assembly took a full quart of 90 wt oil instead of
the .3 liter described in the manual. Are there different models that
require different amounts of oil and may have different seal
strategies?

As this is a bi-annual service usually done out of the water, it
would be nice to be very clear about what is required to maintain the
water tight integrity of the boat!

Mike Ondra
Aletes SM200#240

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