Yanmar SD50 saildrive with emulsified oil - how to make a 6 hour journey

[Skylark]

Checked fluids today and found emulsified oil in the SD50 saildrive. It was fine when I last checked, about a month ago, and the engine has not run in that time. It is 4 years old and has less than 200 hours on the meter. The boat was originally fitted with a very lightweight 3-blade aluminium prop and I changed this over its first winter for a very heavy Flex-o-Fold. I suspect, but have no evidence in support, that the weight of the prop has sprung the lower shaft seal. Any views on this?

My haul-out is in less than a month. Regretfully, I have to make a 6 hour / 35 mile journey from marina to yard (the travel hoist at my home marina isn't wide enough to take my beam). I'm thinking about removing as much oil as possible with a hand extractor (not easy on the SD50, I usually remove the drain plug when on the hard) and topping-up with new immediately prior to setting off. The SD50 uses the eyewateringly expensive Quicksilver High Performance Gear Oil. How does this sound.....any better ideas?

Looking forward, any tips on replacing the lower leg seal (assuming it's the problem)? How about availability of the seal....recommend a good, reputable source?

TIA for any help and advice

 

[RichardS]

The first thing to note is that the change interval for the shaft seals is probably every 2 or 3 years but they can go anytime. 200 hours is very low but I doubt that the prop is responsible as there will be very little play in the bearing so the seals should not come under any real stress. If the bearings are gone then the seals will go quickly but after 200 hours I don't see that as a real possibility. It's just bad luck.

There must be millions of saildrives running around with water in the oil so I wouldn't actually worry about a few weeks. I spotted one of mine had gone in August but couldn't change it until the following April and it was fine. However, it certainly won't do any harm to change as much as you can if you are really bothered but don't bother using the marketing-led Quicksilver oil ..... any GL4 or, even better, GL5 gear oil of the right viscosity, 75W-90 or whatever, will be exactly the same.

The seals are easy to change assuming that it's the same as the SD20 where I've changed both of mine. I just bought the cheapest genuine Yanmar ones I could find online.

Richard

 

[Skylark]

Helpful as ever, Richard, thank you.

 

[Baddox]

It's odd that an emulsion has formed without running the engine. Even if water had found its way into the oil, it would require energy, such as the engine running or drive shaft turning, to shear it into an emulsion.

I too would pump out the old oil and replace with some cheap new oil and do it as soon as possible to minimise risk of corrosion. Locking the gearbox in gear may help reduce water ingress caused by the prop and drive shaft moving.

 

[scottie]

The first thing to note is that the change interval for the shaft seals is probably every 2 or 3 years but they can go anytime. 200 hours is very low but I doubt that the prop is responsible as there will be very little play in the bearing so the seals should not come under any real stress. If the bearings are gone then the seals will go quickly but after 200 hours I don't see that as a real possibility. It's just bad luck.

There must be millions of saildrives running around with water in the oil so I wouldn't actually worry about a few weeks. I spotted one of mine had gone in August but couldn't change it until the following April and it was fine. However, it certainly won't do any harm to change as much as you can if you are really bothered but don't bother using the marketing-led Quicksilver oil ..... any GL4 or, even better, GL5 gear oil of the right viscosity, 75W-90 or whatever, will be exactly the same.

The seals are easy to change assuming that it's the same as the SD20 where I've changed both of mine. I just bought the cheapest genuine Yanmar ones I could find online.

Richard

Don't even think about using it if you can avoid it
The Sd50 has a reputation for slipping

http://www.cruisingworld.com/saildrive-maintenance#page-3

Just had a £6000 bill for one with water in it ended up replacing with sd60

 

[Skylark]

It's odd that an emulsion has formed without running the engine.

Good point. More fully, I ran the engine and gearbox, while tied to the pontoon, for about 10 minutes, then checked the fluids after a few more minutes, per the recommendations.

Don't even think about using it if you can avoid it
The Sd50 has a reputation for slipping

http://www.cruisingworld.com/saildrive-maintenance#page-3

Just had a £6000 bill for one with water in it ended up replacing with sd60

I've read the article before but thanks for posting.

The SD50 is not Yanmar's finest piece of work, imho. I don't have an option but to travel 35 miles to haul-out. I can only hope the conditions allow me to sail most of it. I will try to hand vacuum pump as much as possible out and refill with Quicksilver before making the journey. Having read so much widespread negative press, I fear for the wellbeing of the cone clutch so will not use ordinary gear oil.