# shaft vs. saildrive



## jadkkd (Aug 8, 2007)

Have been hearing several concerns about boats with a saildrive sytem for power, that the saildrive is a a maintainance concern especially in the waters of New England. Electrolysis is a major concern


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## deniseO30 (Nov 27, 2006)

just a big hole in the bottom of the boat. (imho)


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## Fstbttms (Feb 25, 2003)

Why would the waters of New England be an issue? How are they any different than anywhere else?


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## jadkkd (Aug 8, 2007)

I'm certainly not an expert and am the last person to know but electolysis a bigger issue on the east coast?


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## Fstbttms (Feb 25, 2003)

jadkkd said:


> I'm certainly not an expert and am the last person to know but electolysis a bigger issue on the east coast?


No. Saltwater is saltwater. We are not talking about some force of nature on a regional scale. Corrosion issues are generally due to a problem aboard the specific boat in question and have nothing to do with where in the world the boat lives.


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## jadkkd (Aug 8, 2007)

ok but would the corrosion be a biiger problem on the saildrive?


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## Fstbttms (Feb 25, 2003)

Saildrive legs can corrode, but properly maintained and protected by zincs, they are no more prone to this than shaft/prop arrangements.


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## rockDAWG (Sep 6, 2006)

Fstbttms said:


> Saildrive legs can corrode, but properly maintained and protected by zincs, they are no more prone to this than shaft/prop arrangements.


Agree. THe proper use and maintained are the key. I believe SD is a viable alternative. As we gain more experience on SD, it will replace the shaft. I hope the engineers are working on one that can rotate from side to side (left and right). Bow truster will be replaced.

If the hull is properly designed and the SD is properly installed. A big hole at the bottom of the hull is my least concern.


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## Omatako (Sep 14, 2003)

rockDAWG said:


> If the hull is properly designed and the SD is properly installed. A big hole at the bottom of the hull is my least concern.


Nahh - SD can't swim nearly fast enough!


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## killarney_sailor (May 4, 2006)

Someone I know and respect who has a great deal of experience with sail drives recommends not using the water intake that is part of the sail drive. Rather, seal the intake with epoxy and fill the leg with antifreeze mix. Then get your cooling water through a conventional through hull. Not having sea water on the inside of the leg will dramatically reduce the possibility of corrosion - and yes, you still need to keep a close eye on your zincs.


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## tommays (Sep 9, 2008)

Well

Despite all manufactures best efforts due to the cost of the correct alloy like they use on the newest Volvo pods for powerboats they make a compromise based on cost 

The Saildrives life very much depends on the complex factory finish as marine life gets scraped off over the years damage to the finish makes it very easy to have problems 

And like there outdrive brothers there is nothing between the drives oil supply and the water BUT two oil seals


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## PCP (Dec 1, 2004)

Fstbttms said:


> No. Saltwater is saltwater. We are not talking about some force of nature on a regional scale. Corrosion issues are generally due to a problem aboard the specific boat in question and have nothing to do with where in the world the boat lives.


I have a question to you. Volvo Penta recommends to change the saildrive main seal every 7 years. When my boat was 8 years old I have asked for a very experienced shipyard (Sardinia) to have a look at it to see if it should be replaced. They had a look at it and have said: Nah, it is in good conditions. I have asked them when should I replace it and they have said: when it needs to be changed 

Now, in your experience what is the average duration of that seal?

Regards

Paulo


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## Fstbttms (Feb 25, 2003)

PCP said:


> INow, in your experience what is the average duration of that seal?


You are asking the wrong guy. All I know about saildrives is what I see and do when I'm cleaning them underwater. I am in no way a mechanic.


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## DwayneSpeer (Oct 12, 2003)

PCP said:


> I have a question to you. Volvo Penta recommends to change the saildrive main seal every 7 years. When my boat was 8 years old I have asked for a very experienced shipyard (Sardinia) to have a look at it to see if it should be replaced. They had a look at it and have said: Nah, it is in good conditions. I have asked them when should I replace it and they have said: when it needs to be changed
> 
> Now, in your experience what is the average duration of that seal?
> 
> ...


My Volvo saildrive is 32 years old. I've had it 12 years. I've never changed the seal and it hasn't leaked.

The zinc on the saildrive is huge! But I've only had to replace it once and then it didn't really need replacement. I replaced it "just because".

I love my saildrive!!!!!


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## Faster (Sep 13, 2005)

PCP said:


> I have a question to you. Volvo Penta recommends to change the saildrive main seal every 7 years. When my boat was 8 years old I have asked for a very experienced shipyard (Sardinia) to have a look at it to see if it should be replaced. They had a look at it and have said: Nah, it is in good conditions. I have asked them when should I replace it and they have said: when it needs to be changed
> 
> Now, in your experience what is the average duration of that seal?
> 
> ...


Paulo

For reference, friends of ours with a 2002 Bene 36.7 recently had the seal changed in Guadaloupe based on the 7 year recommendation... the yard that did it told them the old seal would have been fine for a long time to go yet..


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## PCP (Dec 1, 2004)

DwayneSpeer said:


> My Volvo saildrive is 32 years old. I've had it 12 years. I've never changed the seal and it hasn't leaked.
> 
> The zinc on the saildrive is huge! But I've only had to replace it once and then it didn't really need replacement. I replaced it "just because".
> 
> I love my saildrive!!!!!


That's very impressive!!! I did not even know that the saildrive concept was more than 30 years old



Faster said:


> Paulo
> 
> For reference, friends of ours with a 2002 Bene 36.7 recently had the seal changed in Guadaloupe based on the 7 year recommendation... the yard that did it told them the old seal would have been fine for a long time to go yet..


thanks. I guess your friends were not as lucky has I was. Now I understand why the owner of that shipyard implied that I was crazy to want to change a seal in perfect conditions

It seams that the 7 years are a kind of safety measure taken by volvo-penta to be absolutely sure that no claims are made on the ground of defective main seal of the sail-drive. It seems also that Paolo (the owner of the shipyard) was right when had said : "We change it when it needs to be changed".

32 years? Jesus   

Regards

Paulo


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## rockDAWG (Sep 6, 2006)

So Mark Twain is right: The report of the Saildrive death have been greatly exaggerated. Damn internet, again. 

Likewise, the purpose of manufactures choose to use drivesail is to save manufacturing cost and purposely pass the frequent and difficult maintenance to the consumer is unfounded.


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## jrd22 (Nov 14, 2000)

I wouldn't have one, but that's just because I have a lot of experience with outdrives on power boats, but that's not to say they don't work for some people. They are MUCH more complicated than a shaft drive (gears, bearings, seals, aluminum housing, etc), that's enough of a reason to go with a shaft imho.


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## sailingdog (Mar 19, 2006)

One reason saildrives have gotten a bad rep is that there were some, notably OMC as an example, which had a very bad track record. Properly installed, a saildrive can make a lot more sense and be a much more reasonable solution than a traditional prop shaft setup. There's no stuffing box to worry about, and the prop walk issues are not as noticeable, since the prop on a saildrive is perpendicular to the waterline, rather than angled as a traditional propshaft would require.


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## MJBrown (Apr 1, 2009)

You'll start seeing more saildrives from Beneteau and Jeanneau and who knows who else. They're coming out with joystick systems that will allow you to walk the boat sideways for easier docking. It's basically a takeoff of the Volvo IPS drive on a power boat, Hinkley jet drives and others. Saildrives are used since they can rotate. Something key to the joystick system.


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## Faster (Sep 13, 2005)

MJBrown said:


> ....Saildrives are used since they can rotate. Something key to the joystick system.


I know such drives exist, primarily on Harbour tugs and ferries, but to date few sailboat saildrives are the 'rotatable' type (known as "Z" drives, I believe)

I think they'd be cost-prohibitive.... but then so's a carbon rig......


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## MJBrown (Apr 1, 2009)

Well stay tuned because Beneteau has already announced it and will likely have literature on it at the Annapolis Show. Jeanneau already has a sail drive on the 45DS that will be at the show. Thier version of joystick control is right around the corner.


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## sailingdog (Mar 19, 2006)

MJBrown said:


> Well stay tuned because Beneteau has already announced it and will likely have literature on it at the Annapolis Show. Jeanneau already has a sail drive on the 45DS that will be at the show. Thier version of joystick control is right around the corner.


Actually, Jeanneau announced this not too long ago... but that's not too surprising, since they're owned by Bendytoy.


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## PCP (Dec 1, 2004)

Beneteau has also a new control system by joystick. Take a look at the video:

http://www.beneteau.com/fr/voile/default.aspx

http://www.beneteau.com/UserFile/File/Voile/Actualites/dockandgo/Docks&Go.pdf


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## Plumbean (Dec 17, 2009)

DwayneSpeer said:


> My Volvo saildrive is 32 years old. I've had it 12 years. I've never changed the seal and it hasn't leaked.
> 
> The zinc on the saildrive is huge! But I've only had to replace it once and then it didn't really need replacement. I replaced it "just because".
> 
> I love my saildrive!!!!!


How huge is that zinc? I have a Yanmar saildrive, which has two zincs. One is a pencil style inside the boat and the other wraps around the prop shaft. This is only my second season with the engine, but the zinc that wraps the prop shaft was only good for a season and was replaced prior to launch this spring. The pencil one didn't seem to have any wear at all.

BTW, very happy with the engine so far, but potential buyers should be aware that the only way to change the gear oil in the saildrive leg (SD 20 model) is to haul the boat. Not a problem for me, since I have to haul every winter anyway. I don't think this is the case for the SD50.


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## MJBrown (Apr 1, 2009)

Dog, I hadn't heard about the Jeanneau announcement. Guess I better brush up on the brand since I'll be boat sitting in Jeanneaus at the show this year. Been delivering boats to the show for a friend and broker the last few years. Going to help out with the boat sitter part this year. Something new and hopefully fun. Can't be all bad getting to hang out on new boats and talk sailing for a few days 
Mike


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## DwayneSpeer (Oct 12, 2003)

Plumbean said:


> How huge is that zinc? I have a Yanmar saildrive, which has two zincs. One is a pencil style inside the boat and the other wraps around the prop shaft. This is only my second season with the engine, but the zinc that wraps the prop shaft was only good for a season and was replaced prior to launch this spring. The pencil one didn't seem to have any wear at all.
> 
> BTW, very happy with the engine so far, but potential buyers should be aware that the only way to change the gear oil in the saildrive leg (SD 20 model) is to haul the boat. Not a problem for me, since I have to haul every winter anyway. I don't think this is the case for the SD50.


Yup, it's the one around the prop shaft and just guessing, it weighs in around two or three pounds.

Yup, you have to haul out to change oil but you only need do that if there is a problem such as a leaking seal. Otherwise it will last forever since oil doesn't break down in a gear box unless you get it real hot. I did have to change mine once when I found water in it. When it was hauled I found that the basta*** at the old yard had put on a cheap paper seal on the oil drain plug after doing some work on it for me the previous year.


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## rockDAWG (Sep 6, 2006)

MJBrown said:


> You'll start seeing more saildrives from Beneteau and Jeanneau and who knows who else. They're coming out with joystick systems that will allow you to walk the boat sideways for easier docking. It's basically a takeoff of the Volvo IPS drive on a power boat, Hinkley jet drives and others. Saildrives are used since they can rotate. Something key to the joystick system.


TO my understanding, Beneteau sail drive does not rotate. The Deck and Go system Beneteau is going to introduce in the "Sense" series use combination of saildrive and bowthruster.


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## PCP (Dec 1, 2004)

rockDAWG said:


> TO my understanding, Beneteau sail drive does not rotate. The Deck and Go system Beneteau is going to introduce in the "Sense" series use combination of saildrive and bowthruster.


No, you get it wrong. It is a combination of saildrive and bowtruster that is managed by a computer, but the sail drive rotates 360º.

"For easier manoeuvring when coming alongside, the

bowthruster is synchronised with a 360° pivoting saildrive base
by the use of a controller. The helm stays locked automatically​during the manoeuvre."

http://www.beneteau.com/UserFile/File/Voile/Actualites/dockandgo/Docks&Go.pdf

The system will also be available on other sailboats (not only in the Sense series).

Regards

Paulo​​​


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## rockDAWG (Sep 6, 2006)

Papitão , 

Good to know. But if the saildrive can rotate 360 degrees, it is 10x better than someone using prop walk to turn to boat. Do we really need a bowtruster?


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## bacampbe (Mar 17, 2009)

Not much to go wrong with that!


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## jrd22 (Nov 14, 2000)

bacampbe said:


> Not much to go wrong with that!


:laugher :laugher :laugher :laugher


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## Omatako (Sep 14, 2003)

Plumbean said:


> BTW, very happy with the engine so far, but potential buyers should be aware that the only way to change the gear oil in the saildrive leg (SD 20 model) is to haul the boat. Not a problem for me, since I have to haul every winter anyway. I don't think this is the case for the SD50.


Well it could be a problem if you, for example, get a piece of fishing line wrapped around the shaft. My experience with stern drives is that a piece of line will not rest until it has destroyed the seal and ended up inside the gearbox.

When this happens and you don't know, you'll end up draining the gears with the oil and good luck doing this while you're sailing around the Marshall Islands (for example) where the nearest haul-out is 3000nm away.

No, a saildrive is not for me.


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## sailaboat (Oct 3, 2010)

*saildrive*

Hi
I have had a saildrive on my 34ft yacht in the UK since 1992. Here electrolysis is not a problem. I change the anode every year, of which there are 2 on the saildrive unit. The unit has worked perfectly since the day the boat was launched

Tim


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## olson34 (Oct 13, 2000)

*Time and Money?*



sailaboat said:


> Hi
> I have had a saildrive on my 34ft yacht in the UK since 1992. Here electrolysis is not a problem. I change the anode every year, of which there are 2 on the saildrive unit. The unit has worked perfectly since the day the boat was launched
> 
> Tim


Tim, Do you dive it yourself, pay a diver to change those anodes, or have the boat hauled out each year?
What is your schedule for SD diaphram changeout? How many hours labor is needed?
Thanks.


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## sailaboat (Oct 3, 2010)

Hi
The anode lasts well over 100 hours of engine running time which does us each year. I lift the boat once a year for antifoul painting etc and change the anode then. Only takes 10 minutes. The diaphragm has never been changed and has never leaked and looks in good condition 
Regards
Tim


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## PCP (Dec 1, 2004)

rockDAWG said:


> Papitão ,
> 
> Good to know. But if the saildrive can rotate 360 degrees, it is 10x better than someone using prop walk to turn to boat. Do we really need a bowtruster?


I don't think you really need any of those if you have a 40ft boat. On bigger boats, in many marinas you don't need them also. The problem is that today on very crowded marinas they put 42 feet boats in places that where designed for 36 ft boats and you just don't have space to maneuver.

Answering your question, yes I think that if you have a rotating saildrive, you would have already a big help and the bow thruster would be just too much. But one thing is what you need, other the needs created by marketing...hell, do you believe that I saw once a Bavaria 32 with a bow thruster    

Regards

Paulo


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## killarney_sailor (May 4, 2006)

*Powerboat with more*



PCP said:


> .hell, do you believe that I saw once a Bavaria 32 with a bow thruster
> 
> Regards
> 
> Paulo


I saw a 28' powerboat with twin inboards and a bow thruster - I was blown away by it, trying to figure out why anyone would bother. I guess the stern thruster was being added later.


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## rockDAWG (Sep 6, 2006)

killarney_sailor said:


> I saw a 28' powerboat with twin inboards and a bow thruster - I was blown away by it, trying to figure out why anyone would bother. I guess the stern thruster was being added later.


Hey What I can I say. There are ricers in every sport


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## corbin39 (Mar 28, 2011)

Fstbttms said:


> No. Saltwater is saltwater. We are not talking about some force of nature on a regional scale. Corrosion issues are generally due to a problem aboard the specific boat in question and have nothing to do with where in the world the boat lives.


I own a Corbin39 sailboat with a Volvo saildrive. I am fortunate I moor in San Francisco Bay where the water is free of acids and am in a marina where electrolysis is checked regularly. My zinc is very slow to corrode. Still, I have a diver check the drive every 3 months. I use no bonding on the boat. The drive is 25 years old but is still in good condition. Corrosion DOES depend "on where the boat lives".


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## motion300 (Feb 12, 2009)

There is a lot to be said about the simple shaft and rudder system simple and relaible


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## night0wl (Mar 20, 2006)

motion300 said:


> There is a lot to be said about the simple shaft and rudder system simple and relaible


Much truth in this statement, but I fear that the days of shaft + rudder are going to be limited. Look at how much traction that the new Beneteaus & Jeanneau's are getting with their Dock & Go system.

Its like a Carburetor system in vehicles...everyone's moved onto fuel injections now. I think in 20 years, very few boats will come wiht shaft + rudder vs "pod" or z-drive/saildrive systems.


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## RichH (Jul 10, 2000)

The vulnerability of the saildrive system should not be understated. If you hit a log or other large underwater object you can easily crack the housing, etc. and you will have "one hell of a time" stopping the flooding. 

I had the 'opportunity' to help a large catamaran who had struck a log (?) and 'split' the casing of one of his saildrives. It became impossible to stop the water flow coming up through the broken saildrive. The only way we 'saved' the boat was to 'seal' the one hull and let the incoming water 'pressurize' it .... the one hull only 'sunk' halfway then 'stabilized'. The USCG arrived about 30 minutes later with a huge pump to save the day. 
Saildrives .... nope, you can keep 'em.


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## DwayneSpeer (Oct 12, 2003)

DwayneSpeer said:


> My Volvo saildrive is 32 years old. I've had it 12 years. I've never changed the seal and it hasn't leaked.
> 
> The zinc on the saildrive is huge! But I've only had to replace it once and then it didn't really need replacement. I replaced it "just because".
> 
> I love my saildrive!!!!!


I've now changed my seal twice since my original post here! Once as a purely preventative measure about 5 years ago and again 3 years ago when the boat yard picked my boat up with the rear sling under the drive and tore everything loose including the engine mounts! That lift cost the yard a lot of money for their mistake!

But I still wouldn't trade my saildrive for anything.


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## spec2 (Mar 1, 2009)

This was my commissioning list for my SailDrive (Volvo MD2020 – 2003 C&C)
•	Replace fuel filter
•	Drain the oil from the Sail Drive on Propeller housing
•	Change Reverse Gear Oil
•	Install new raw water impeller
•	Inspect Sea Cocks
•	Replace all Zinc's on Sail-drive
•	Coolant Level Check
•	Engine Oil Level check - make sure not over-filled
•	Inspect Sail Drive Rubber Boot Seal and stainless ring - 7years old now
•	Clean out SailDrive leg intakes
•	Check raw inlet system for blockages and barnacles
•	Inspect heat exchanger and clean the core if needed
•	Replace thermostat and inspect heat exchanger pressure cap
•	Inspect all engine compartment hoses - replace as needed
•	Inspect engine mounts
•	Inspect Engine Belt
•	Inspect/clean sea strainer


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## Noelex (Jan 23, 2008)

spec2 said:


> This was my commissioning list for my SailDrive (Volvo MD2020 - 2003 C&C)
> 
> •	Inspect Sail Drive Rubber Boot Seal and stainless ring - 7years old now


I think you have got quite a bit of expensive and difficult work coming up..


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