experiences with saildrives, problems?

[sundog]

So I checked out a boat I really liked this weekend that was equipped with a couple yanmar 2GMs with saildrives.... with 7000 hours. The boat is a 96. Personally I've had zero experience with saildrives but to me putting a chunk of aluminum filled with steel underwater permanatley and sealing it with a piece of rubber seems like a bad idea, even more so for an oceangoing boat. I'd like to hear about experiences people have had with aging saildrives.

[imagine2frolic]

My boat was launched in 98, and the motors have right at 3000 hours. The only problem I have had is to change the lower seals. The units ar SD20's on 30GM's, SO FAR SO GOOD?

[Tellie]

Sundog putting anything metal in salt water is a bad idea, but whatdaya gonna do you need propulsion.
I have the same set up as you describe with about as many hours. They still, knock on wood, run great. Although I do spend plenty of time in the water keeping the nasties from growing too prolific. Special care has to be paid to the cooling water intakes, I find they're a bit small and it doesn't take much growth to block them up. There's also plenty of room for growth up in between the sail drives, hull and boots. I'm also glad I have a Hookah set up just for this underwater maintenace. The biggest pain I find is replacing the seals on the sail drive. I've had Yanmar tell me they like to see this done each year. In my experiance I find that a bit often. I keep a close check on the saildrive oil for any signs of water. The boat has to come out of the water for seal replacement and I'm assuming you were looking at a Cat, finding a place to get these things hauled is another thing to consider. I change the sail drive oil every other engine oil change, that's a bit excessive but I suck it out from the fill port and you can't get it all, but I figure oil is cheap sail drive units are not.. To completely change the oil the boat needs to be out of the water. The zincs just in front of the props are fairly substaintial and I've never found they weren't in great condition when I do haul out, but cheap enough to replace anyways. When I first got my boat I was worried about the leverage that seemed could be placed on the engine, boots etc if the saildrive struck bottom. But I've dragged my fair share of lobster pots wrapped around the drive and so far no apparent problems. If you ever replace those yanmars you'll be smart to replace the sail drives as well. Something to consider for future costs. All in all two yanmar sail drive units are twice the maintenace, but if it's the Cat I'm thinking it is the benifits far out weigh the extra considerations.

[sundog]

Thanks for the good info. About changing seals/boots... how long does this take (can it be done between tides with the boat beached?) My main concern is electrolysis -and getting major work done in remote places. Though I also have to wonder what would happen if you hit something really solid with one (log, ect)... would you just snap/bend the whole thing or is it going to try to snatch the whole tranny (and boot) out of the hull. Just pondering the worst case scenario stuff -would probably never happen.

[Tellie]

I'm no expert, Maybe NeverMonday could chime in, and I haven't changed out my boots yet but knowing the size of the hole you'll have that's not a job I'd leave for low tide. I've been looking on the web myself for the procedure to change out boots. I understand two years is the recomended time interval. Mine are older than that and seem supple enough with no leakage or signs of cracking. I'm assuming there would not be a major failure of the boot all of a sudden. I'm sure the signs to replace it would start out subtle and give you plenty of time to work out a place and time to haul out. These are actually double diaphrams with a water alarm in between for extra safety. I also ponder the worst case senario stuff as well, a Cat can gain some pretty good speed under sail, whacking an inmoveable object like a rock or coral head would have to transmit some serious force. I would hope the keel would block the impact or at least reduce most of the impact. But then again, I never go aground <grin>
My saildrives are original and I can't find any problems as of yet with electrolysis. Other than expected wear and tear they are in pretty good shape.
So what make of boat is this that you are looking at?

[ssullivan]

I have Yanmar SD20 saildrives with the 30hp Yanmar engines as well.

I, too was very nervous about the whole idea of aluminum and whatever just sitting below a boat for long periods of time.

While I do have a leaking lower seal on one of them (was like this when I bought the boat - found evidence the PO covered this one up), it seems as though they are *reasonable* propulsion devices.

My big issues is with those oil changes on the SD20's. They service interval is 100 hrs, yet you have to haul the boat for that?? Are they idiots?? Yes.

So, I plan to do like most and suck out approximately half from the fill hole, providing a complete change every 200 hours. The zincs do not seem to wear away, and in my case... in a hot marina, the props actually were eaten away without damage to the saildrive unit. Pretty good test, huh?

They are more complicated and annoying than a standard linear drive shaft. But... if the boat you are looking at has everything else you want... don't say no only because of saildrives.

But... I guess it's important to note that they are pretty reliable. Mine are from 1985 and have outlived a set of Yanmar engines that were tied to them. The new Yanmars engines only have 400 hours on them, but I think there is a lot of life left in the saildrives (other than seals).

[Connemara]

Have an '82 saildrive that works like a charm.

If I want to service the lower unit, I have to pull it out of the hole it sits in. But I'm told -- haven't done it yet -- that it just plops back in, a bit of sealant, and Bob's yer uncle. There is no leakage around the seal now and I'm told by the PO there never has been any.

Consider that yer gonna have something in the water anyway. For my money, a saildrive is a reasonable option, because the water is sealed out of the boat ... unlike a propeller shaft, where the stuffing box is designed to leak and in the worst case, will let lots of water in very quickly.

The collision issue is a real worry, but I've got a monohull, so anything that's gonna hit the saildrive is gonna hit the keel first.

My $0.02 worth.

Connemara

[camaraderie]

Wasn't there a problem with Yanmar saildrives in the 2005 or so time frame having big corrosion problems due to the use of a bad alloy? As I recall, this surfaced on Tartans and they dropped Yanmar as a supplier over the issue.

[imagine2frolic]

I would say the bottom shaft seals take about 30 minutes to replace each. You need a bucket to accept the lube. Something to stop the spin of the prop, and a wrench, I think it was 24mm?

[ssullivan]

Really??

This is great news. I haven't been in there yet, and would love to do this between tides, rather than have an expensive haul-out at a marina.

Can you put the prop in gear while taking it off the help stop it?

I'm pretty excited to make this repair. Your little tip here may just have saved me a haul out on this delivery. The saildrive was the whole reason I was thinking about hauling out.

Any chance you can explain the procedure in a short little paragraph?

I mean, I know you take the cone off, and the prop off, but then what's behind that? How do you get the seal out? Does it come right out with your hands, or do you need to pry/pull it with a tool?

Is there any trick to fitting the new seal?

Thanks in advance!

Originally Posted by imagine2frolic

I would say the bottom shaft seals take about 30 minutes to replace each. You need a bucket to accept the lube. Something to stop the spin of the prop, and a wrench, I think it was 24mm?

[Steve Rust]

I have a 1982 Volvo saildrive. It has been trouble free. I have replaced he lower seals and it was not difficult. On the Volvo the lower seal is pressed into a housing that is held in place by two small machine screws. There are also two O rings that form a seal between this housing and the salldrive body. It is very important to keep an eye on your zincs and replace when necessary. To replace the main seal is a haul out job.

[sundog]

Great, all good info and mostly good news. The vessel under consideration is an FP Athena. I haven't had the chance to visually inspect anything underwater yet but if things progress of course I will. Just for fun does anyone know what one of these suckers costs?
Thanks all.

[ssullivan]

So it's not a 1/2 hour job then??

I wish I could get reliable info (agreeing info) on how to do this lower seal. A service manual would be nice, if I could find one. Anyone have one?

One of my main goals in buying a cat was to avoid marinas. I if a repair can be done between tides (in 3-4hrs), I would like to do it between tides.

Originally Posted by Steve Rust

I have a 1982 Volvo saildrive. It has been trouble free. I have replaced he lower seals and it was not difficult. On the Volvo the lower seal is pressed into a housing that is held in place by two small machine screws. There are also two O rings that form a seal between this housing and the salldrive body. It is very important to keep an eye on your zincs and replace when necessary. To replace the main seal is a haul out job.

[imagine2frolic]

I had a yanmar dealer fax me a blow apart diagram. I think it is still on the boat. I will look for it. I was doing my bottom, and standing next to the mechanic when he pulled it apart. I was embarrassed I didn't do it myself. He had the lower unit out in 5 minutes, and was gone for ten, and then slipped the unit back in in 5. It took him longer to add the oil than do the job. If I remember correctly there were only 2 "O" rings on the bottom.

When the boat was launched the yard wanted to charge me for 3 hours, but I brought to their attention how long it really took, and they reduced the bill accordingly.

[ssullivan]

Now we're talking!

Thanks. If you can find that exploded diagram, it would be very helpful, so I don't have to do one drying out for exploratory work, then a 2nd for the actual work. I can go right at it if I already know what to look for.

I'm on the hard right now - on the tide hard.

I'm going to have a quick look at things while I put on a zinc that was missing as well as srape some growth off. Maybe take a look at removing those prop cages as well.

Originally Posted by imagine2frolic

I had a yanmar dealer fax me a blow apart diagram. I think it is still on the boat. I will look for it. I was doing my bottom, and standing next to the mechanic when he pulled it apart. I was embarrassed I didn't do it myself. He had the lower unit out in 5 minutes, and was gone for ten, and then slipped the unit back in in 5. It took him longer to add the oil than do the job. If I remember correctly there were only 2 "O" rings on the bottom.

When the boat was launched the yard wanted to charge me for 3 hours, but I brought to their attention how long it really took, and they reduced the bill accordingly.