# Saildrive vs shaftdrive



## TSOJOURNER (Dec 16, 1999)

I'm considering a purchase of a new Tartan. The engine is a yanmar diesel with a saildrive...would appreciate feedback concerning the pros & cons of 
this setup.

Thanks, Raydaddy


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## Giulietta (Nov 14, 2006)

Ray,

Saildrive is probably one of the best inventions of the last decade for sailboats. My choice when building our boat. And beats the shaft nightmare once and for all.

It completely avoids all the problems of shafts, corrosion, seal, vibration etc.

It allows to install the engine as far forward as possible (no need to keep angle for shaft), to optimize weight. It seals with a seal that lasts at least 7 years and is easily replaceable. Yanmar even includes a seal broken alarm with their engine panel!!

Allows use of larger props, because engine column is farther appart from hull, allow engine to be horizontal, no thru hulls for cooling water suction, etc.etc.

And the list goes on and on.

Downs are few, but include:

There is a small really insignificant decrease of efficiency due to added gear drag, but its not even visible.

Some added weight due to Saildrive weight, almost 45kg more.

Need to get boat of the water to replace Saildrive gear oil. Takes 3 hours or more to suck from the top, almost impossible.
Need special paint to protect column as anti-fouling will corrode it (this almost scared me, as I tought my saildrive had been painted also, but we're ok, they used Saildrive paint, ufff)

Here a few photos. Should you have any more questions, please ask.

Yanmar's photo from my manual.










And my saildrive with racing folding prop.


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## tdw (Oct 2, 2006)

G,
I've always worried about the size of the hole you need in the bottom of the boat so I've shied away from saildrives. Question for you, do they leak at all ? Seems one of the great advantages would be no need for a stuffing box/gland and ergo no leaks but is this correct?
Cheers
Andrew


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## Giulietta (Nov 14, 2006)

tdw said:


> G,
> I've always worried about the size of the hole you need in the bottom of the boat so I've shied away from saildrives. Question for you, do they leak at all ? Seems one of the great advantages would be no need for a stuffing box/gland and ergo no leaks but is this correct?
> Cheers
> Andrew


ZERO LEAKAGE!!

Unless the seal is damaged, which is really almost impossible.

The saildrive seats on a round seat, part of the engine mount. It then is bolted to that round seat, and water is allowed inside. But it does not come out, because it is a tight fit and well bolted.

See photo of by engine / saildrive bed piece.

See the round part?? That is where the saildrive bolts and the sail drive just looks like a big flange. They say the seal should be replaced every 4 years, but I have a lazy friend that has had his for over 7 years now, and inspection by Yanmar said no need for a new one!!










excuse the dust and mess....it was on purpose to keep paint drops and resin from staining.

But even if the seal broke, the amount of rubber is so small that any bidge pump could easily take it out! I've installed one, just in case. Still dry!!


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## tdw (Oct 2, 2006)

Well then it's all good. Thanks for that mate, guess I'll have to put that particular prejudice to one side.
Cheers
Andrew


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## [email protected] (Mar 27, 2004)

Hello Giu- the PO of my Pearson 365 had a SD31 installed with a Yanmar 3JH3CE - in the winter of 1999. There are less then 400 hours on the engine. Three questions - 1) what paint do I use for the outdrive casing, 2) I am preparing for a 14 month cruise, what maintenance should be done on the saildrive prior to leaving - I had it inspected by a yanmar certified technician but he did not recommend changing the seal - Though I am not impressed with the thoroughness of the yard - however they certainly charge enough 3) The antifreeze used for the Yanmar was the green stuff - the technician said that I should flush, soak (remove the reservoir and holding tank)and replace with the orange antifreeze - is this recommended or are they trying to soak me.
Thanks for your help and input - 
So far (one season with boat) I am very happy with the saildrive (have maxprop three blade folding) I did have a problem with lobster pot line getting hung up on the drive (while sailing) and I do worry that the only way to work on them is out of the water- but so far spotless performance.


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## Giulietta (Nov 14, 2006)

Aschoenb,

1) I made that question too, some time ago. YOU MUST NOT use bootom paint, as it corrodes the column. We used a dedicated columnd primer paint, and then an antifouling paint. They were done by the yard that built her, and they said they ordered it from Jotun. Interlux also carries it.

2) No maintenance, other than run a wire once every 2 years, thru the water intake hole, just to clean any "animal" hat decided to make it its home... I change the SD gear oil every year, when washing or painting the hull. Take this opportunity to clean inside hole with wire. Check zincs on prop and column. Check seal inside boat. (do not put any crap on seal, its not a girls lip that requires moisture).
3) Antifreeze here is green, orange and pink. The colour code I don't know, I think its to sell it easier, but any antifreeze is good. There is no "marine" anti freeze, at least here. The cooling system is closed, so no contamination.

Look, to do maintenance on anything under the water, you need to get the boat out anyway. Just time your maint with the outings.

I don't want anything else, maybe the ALL NEW RACING SD, that is thinner and longer.


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## TSOJOURNER (Dec 16, 1999)

One way to determine whether saildrives our a good idea is to see if any top line boat builders are using them. Generally they are not. They are cheaper to install and therefore may have an appeal to some companies. Is Hinkley using them? Shannnon? IP? What about Tartan?


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## Vasco (Sep 24, 2006)

Saildrives might be alright for racing but most cruisers steer clear of them. Many of the newer cruising cats have them and it is a PITA to change the oil as they need to be hauled.


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## TSOJOURNER (Dec 16, 1999)

long

Tartan is using them, as the original question is about a new tartan with a SD. As to whether others are using them, one reason might be the new tooling needed.


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## T37Chef (Oct 9, 2006)

There has been some good discussion about this on the Tartan Owners website: http://www.tartanowners.org/

Good and bad.


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## TSOJOURNER (Dec 16, 1999)

"Antifreeze here is green, orange and pink. The colour code I don't know, I think its to sell it easier, but any antifreeze is good. There is no 'marine' anti freeze, at least here. The cooling system is closed, so no contamination."

_Green_ and _orange_ antifreezes are ethylene glycol based, automotive types. They have lives of two and five years, respectively. They are poisonous, so are for cooling systems only.

_Pink_ antifreeze is propylene glycol based, and is typically used to protect potable systems. An application would be the boat's water tanks when winterizing. It's not poisonous, but flush before re-filling your tanks. I don't know the life of this product, but would not expect it to have additives as the other types do. I have seen it in hardware stores.

Yanmar specifically recommends "low-silicate antifreeze" for their engines. I e-mailed Westerbeke about their non-specific recommendation, and they replied that automotive antifreeze is fine as most of it is low silicate. They did not respond to my question concerning propylene glycol, the _pink stuff_. Yanmar may be supporting their dealerships.


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## Giulietta (Nov 14, 2006)

jones2r said:


> "Antifreeze here is green, orange and pink. The colour code I don't know, I think its to sell it easier, but any antifreeze is good. There is no 'marine' anti freeze, at least here. The cooling system is closed, so no contamination."
> 
> _Green_ and _orange_ antifreezes are ethylene glycol based, automotive types. They have lives of two and five years, respectively. They are poisonous, so are for cooling systems only.
> 
> ...


Jones,

Thank you. Good information on this. Mine is green. But here, with 58ºF in Winter and 90ºF in Summer, we're far from freezing, so green is good.

As far as chosing a sail drive or a shaft, the sd is actually more expensive. I don't know in the US.

I have had both, (for a long time) and chose what I like better, of course, there are allways other wise opinions.


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## TSOJOURNER (Dec 16, 1999)

Giu,

"Mine is green. But here, with 58ºF in Winter and 90ºF in Summer, we're far from freezing, so green is good."

You need to change yours every couple of years (green: two-year life) or it will turn corrosive and damage the pump, etc. In reality, you could just use an additive like water pump lubricant (for corrosion protection) and not bother with antifreeze.

The difference between green and yellow/orange is the additives, hence the difference in life span. The ethylene glycol is what provides the freeze protection. The way chemical companies operate, each will specialize in certain base compounds. For instance, Celanese _used_ to make the majority of the ethylene glycol. Anybody who needed ethylene glycol for a product of their own manufacture would go to Celanese. I don't know the situation since they were acquired by Hoescht. (I would like to say that this situation is current today, but I have to be careful; lurking monitor. I've been in enough trouble here lately.) The difference among brands of antifreeze is the additives, not the base product.


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## [email protected] (Mar 27, 2004)

Hello Jones2r,
You mention that the green antifreeze will turn corrosive after 2 years, however usually the way to determine the functionality of the antifreeze is by density not pH, so is there a way (ex. pH paper) to determine if your antifreeze has gone "bad" and what pH would be deemed "bad" - I am in Maine and the temp is now -4F so this would be good info.
Thanks
Andy


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## TSOJOURNER (Dec 16, 1999)

Andy, 

Hope I haven't caused any confusion here. Antifreeze, unless it is diluted, does not lose its capability to prevent freezing. The life of the stuff is measured by how long it can be used before becoming corrosive.


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## Giulietta (Nov 14, 2006)

Jones, thanks for the tech. input on the coolants. I really appreciated it, as you presented it as an Engineer.

I did not know about the life span and corrosion features of the anti-freeze.

Now, please, one more question, I am pretty sure that the one Yanmar installed on my engine is called a coolant liquid instead of anti-freeze (because we don't have freezing). I'll have to check with them. If the coolant has no anti-freeze will it still have a 2 year life span?? 

Thank you


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## TSOJOURNER (Dec 16, 1999)

Giu,

I only have the rudimentary knowledge of antifreeze that I have imparted. Yanmar has very little info on their website, less so than a few weeks ago (although they are now showing the power/torque curves), so I don't know what their recommended service interval is. If you don't have the service interval in your owner's manual, you would have to follow the website's recommendation of "consult the factory dealer." My best guess is that you have antifreeze in your boat's system; Yanmar wouldn't know or care what your intended sailing grounds would be. The installing dealer should be following Yanmar's procedure in order to validate the warranty.

I can't say for certain that there are not any 5 year anti-freezes that are not green. However, the mfrs indicate that their 2 year products are green. When the 5 year products were introduced a few years back they were all yellow. The mfrs allude to the longer-life products being multi-colored, implying probably not-green. Best bet is to get rid of the stuff after two seasons, but I will relate a caveat. For automotive applications, the life-spans are presented as 30,000 and 150,000 MILE; damned long time in a sailing coastal cruiser. I replaced some of the green stuff in a Ford after 5 YEARS: only had 30,000 miles on it, per the owner's manual. I would not recommend that for your boat's engine.

A third consideration. Yanmar says to use their own antifreeze. Westerbeke does not specify any grade of anti-freeze, only a 5-year service period. My expectation would be that if asked specifically, the mfrs' service rep's would reply to "follow the recommendations in the owner's manual." For the trouble it could cause in your boat (like if the head gasket failed), I would recommend staying with the 2 year, 5 year plan as we have been discussing. In your case, if you used water with an additive as suggested above, change annually.

UPDATE: I found a green product (Zerex) that says its life is 5 yrs/100,000 miles. Their yellow product, extended life of 5 yrs/150,000 miles, is low-silicate. Their orange product, also extended life, is silicate-free.
Guess you have to read the labels these days. I have an empty container _circa_ last year of green product that gives a life of _at least a year_.

Anyway, if you guys aren't thoroughly confused, I am.


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## TSOJOURNER (Dec 16, 1999)

*Boat builders using saildrives*



longwaterline said:


> One way to determine whether saildrives our a good idea is to see if any top line boat builders are using them. Generally they are not. They are cheaper to install and therefore may have an appeal to some companies. Is Hinkley using them? Shannnon? IP? What about Tartan?


I've been told several boat builders are now using saildrives including: Swan & Tartan.

Raydaddy


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## TSOJOURNER (Dec 16, 1999)

*Thanks for responces on saildrives*



Giulietta said:


> Aschoenb,
> 
> 1) I made that question too, some time ago. YOU MUST NOT use bootom paint, as it corrodes the column. We used a dedicated columnd primer paint, and then an antifouling paint. They were done by the yard that built her, and they said they ordered it from Jotun. Interlux also carries it.
> 
> ...


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## Ronbye (Nov 16, 2005)

There are two issues with the saildrive that I would be concerned with.
1. The saildrive housing itself in the water. In our area we have seen saildrive housings completly corroded away over a few seasons. There was no major problems with stary electricity and anodes were used. This is the biggest problem I see. To address this problem, there are some manufacturers who build stainless steel replacement housings.
2. The next problem is the seal itself. They do have to be checked periodically and replace, which involves a haulout or if you are lucky enough with tides, use the careening method. We had an incident where a sailboat with a saildrive lost its seal and almost sunk. Pretty big hole for water to come in. 
So for our area, we recommend to stay away from saildrives.


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## Giulietta (Nov 14, 2006)

"I've been told several boat builders are now using saildrives including: Swan & Tartan."

Raydaddy of course they are....no discussion. 



"There are two issues with the saildrive that I would be concerned with.
1. The saildrive housing itself in the water. In our area we have seen saildrive housings completly corroded away over a few seasons. There was no major problems with stary electricity and anodes were used. This is the biggest problem I see. To address this problem, there are some manufacturers who build stainless steel replacement housings.
2. The next problem is the seal itself. They do have to be checked periodically and replace, which involves a haulout or if you are lucky enough with tides, use the careening method. We had an incident where a sailboat with a saildrive lost its seal and almost sunk. Pretty big hole for water to come in. 
So for our area, we recommend to stay away from saildrives"

Ron, it helps if you specify the make, and year....sounds like pre WWII sail drives to me.

1) SD's need good grounding
2) sounds like real old models to me
3) the seals NOW are very small and last a long time.
4) We remove the boat of the water once a year to paint, any way, don't you?

I assume that what you refer to housing is the column?


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## T37Chef (Oct 9, 2006)

*VW now making Marine engines...*

In the new CW mag (April 2007) I read that Volkswagen is producing a diesel engine with sail drive and engine bed all for around $12,000. There are offering a 40, 50, & 60 HP. They have been a leader in diesel technology in the automotive business for a while, it will be interesting to see how they break into the marine market.


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## Giulietta (Nov 14, 2006)

Those VW were initially an option..Yanmar we chose. enough said


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## Idiens (Jan 9, 2007)

Over here, VW have a ridiculous idea how much their marinised engines are worth. I thought they would be less expensive, bearing in mind how many diesel engines they make for vehicles, but no, their pricing policy is max-profit. I bought a Yanmar (but with a ZF gearbox).


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## luckyjim (Jun 2, 2007)

*Make Sure the Saildrive is Wired Correctly*

SD40 destroyed in 1 year. Replacement SD50 destroyed in one year. Think there is a problem in the wiring of the boat?


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## Idiens (Jan 9, 2007)

I just heard of a new Dehler with similar SD problem. They ended up rewiring the mast and removing the keel. Beware of stray currents.


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## luckyjim (Jun 2, 2007)

Idiens,

I sure would appreciate getting more details if you know them. The mast rewiring is a new twist on the problem. I wonder how the keel was 'bonded' to the engine too. Please submit any and all details you have on the age, model etc.


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## Idiens (Jan 9, 2007)

It started with the boat being delivered with the wrong engine. The engine was changed and the wiring disturbed. This resulted in the saildrive anodes corroding very fast. Checks traced the wiring fault to the mast which in turn lead to the keel. The keel had to be removed and replaced. I was not listening very attentively. I will try to get some more for you.


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## Idiens (Jan 9, 2007)

luckyjim said:


> Please submit any and all details you have on the age, model etc.


This is the letter he got from Volvo. (Try a babelfish translation). The boat and the engine are new this year.

http://i167.photobucket.com/albums/u149/Idiens/VolvoPenta.jpg

It seems that if an insulating ring is broken, the saildrive goes live and eats anodes, but worse can happen.


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## luckyjim (Jun 2, 2007)

Idiens said:


> This is the letter he got from Volvo. (Try a babelfish translation). The boat and the engine are new this year.
> 
> http://i167.photobucket.com/albums/u149/Idiens/VolvoPenta.jpg
> 
> It seems that if an insulating ring is broken, the saildrive goes live and eats anodes, but worse can happen.


OK. I thought it was a Yanmar SD and not a Volvo. The new Volvo design seems to be risky too. Also, the 'installation by marketing' approach does not work for the US if the manufacturer goes by ABYC standards as the 'isolated' leg has to be bonded to the boat's electrical system anyway to meet code. I am sure there will be a lawsuit in there at some stage for US manufacturers that have been switching from Yanmar to Volvo because of the issues with the non-insulated and non-isolated issues with Yanmar sail drives. A big issue seems to be around installation and wiring at the factory. Given what you said about the keel and mast it seems to tell me that while everyone is quick to blame the dock and boats in the marina, the wiring on the boat seems to be by far the biggest factor. Maybe Dehler just had trainee day on that one boat!


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## Goodnewsboy (Nov 4, 2006)

Saildrives can be very good if properly designed and built.

From an engineering standpoint, they have a couple of inherent weaknesses:

1. Complexity, with two right angle gear drives.
2. An oil lubricated gear enclosure that is located underwater. Success depends entirely on the adequacy and longevity of shaft seals.


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## sailingdog (Mar 19, 2006)

They also present another underwater appedage to catch lobster pots and such on. A shaft drive will often be protected by the keel or the rudder skeg, and not be as exposed to catching lines and such. A shaft drive with the prop in an aperture is very well protected, and if a line cutter is attached to the shaft, it becomes almost immune to snagging lines.


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## cockeyedbob (Dec 6, 2006)

port and starboard ... diesel electric ... 360 rotation ... retractable ... wireless remote of course ... hmmmmm, better add the extended warranty!


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## tonybythesea (Jan 15, 2002)

*sail drive corrosion {electrolosis}*

Real BIG problem here folks. Baught the Niagara 35ft last june .Had a diver inspect zincs in Sept. They where ok.Just pulled her out. No zinc left. The bottom of leg corroded and the oil is milky and bubbles. I get the local Yanmah dealer to look at it. {It,s a 31}.

The mechanic said i would have to replace the whole leg an d the only one available is in Japan..$6,500.00 was the price quoted..I think I can do better than that. It still runs good. Got me back to marina . motored 6 hours. I feel it may just need a new caseing and oil seal.

Any ideas or contacts would be appreciated...DESPERATE!

Tony.


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## sailingdog (Mar 19, 2006)

It would help if you said what kind of saildrive it was. What make, model it is? Is it a Yanmar 31? IT would also help if you said where you were located.


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## tonybythesea (Jan 15, 2002)

Yanmah 3JH2..With a 31SD..Bottom of leg Corroded and oil is milky. Do I need a whole new leg $6,500.00 was the quote.

Are there any dealers in US that may have just a new caseing or if I have to replace maybe a refurbished SD at a cheaper cost?


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## tonybythesea (Jan 15, 2002)

I,m trying to contact a company that rebuild SD,s for Yanmar. Mine is corroded and I have been quoted from a local dealer $6,500.00 to replace . Surely there must be a cheaper way. I,m located in BC ,.Canada and I,m hoping to find a rebuild service in the Seatle area..Any ideas..Tony


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