Iron in saildrive oil

[Egovos]

Buying a boat with a Yanmar engine, had saildrive oil analyzed, everything was fine except the Fe was 352 ppm. The reading was marked as excessive. Does any one know what the excess iron imply?

Thank you

 

[kloudie1]

Could mean that the oil has not been changed since new . That would not be unusual for a gearbox "breaking in"
That is a problem with analysis, it is not much good unless there is a good history.. It is useful for contaminants and reading PH and stuff.

or it could mean excess gear wear (and a few other really nasty, expensive things)

 

[Egovos]

My understanding is that the engine doesn’t have “many hours” on it and the boat looks like it has been lightly used

 

[Ted]

When I have my oil analyzed, the lab sends me a detailed report explaining every item that they test for. They keep a record of my oil samples for comparison as well as a history of similar engines/gear boxes. You might want to ask your lab for an explanation. Continue to do oil testing on a regular basis. If the Fe content remains high, you may have a problem brewing. A one time oil analysis doesn't tell the whole story.

 

[Egovos]

Thank you all very helpful

 

[Ralph Johnstone]

My understanding is that the engine doesn’t have “many hours” on it and the boat looks like it has been lightly used

Lightly used probably means lightly maintained which bolsters @kloudie1 's thoughts.

You might consider looking at the condition of the engine. If it shows neglect, this may add a little knowledge to your decision. What is the age of the boat ? Size and any other etceteras such as engine oil condition ? What I'm getting at "what will be the size = cost if the saildrive needs costly repairs" ? Maybe use the lab analysis with high iron as a bargaining tool on price. Ultimately, looking at the potential cost of repairing the saildrive, it would be wise to have a certified mechanic take a very close look at the engine and drive while on the hard.

Could mean that the oil has not been changed since new . That would not be unusual for a gearbox "breaking in"

Very true. Any idea how to change the oil in a saildrive ? Easy, hard ? No experience at all with one.

 

[forbin]

What year and model saildrive? We purchased a boat in 2020 with a 2013 SD50. The Fe was 426 (severe) and water 0.07 (not flagged). The oil didn’t appear to have been changed in a long while (I think never) so I changed it a couple times and re tested after 50 hours. Fe was 70 (not flagged) but water was 0.25 (severe). We ended up replacing the whole sail drive with a SD60 because of the potential costs to get the SD50 “up to spec” with new seals, etc, and the known issues with the drive generally (cone clutches, etc).

So you may find yourself in a similar situation. *If* you do all your own work and don’t mind lapping the clutches and/or fitting the available upgrade kit (not OEM) your decision logic might be different.

Cost for the SD60 installed was ~13k.

 

[Ralph Johnstone]

Cost for the SD60 installed was ~13k.

Shoot me now .

What's involved in changing the oil in the saildrive ? If difficult, the OP may find that the boat he's looking at never had the oil changed either.

What's your opinion of the saildrive you now have as opposed to a simple gland packed shaft ?

 

[Project_Mayhem]

Who took the sample and were there any marks on the drain plug from a wrench/screwdriver before the sample was taken?

 

[forbin]

What's involved in changing the oil in the saildrive?

If it’s an SD50 or newer you can do it in the water, and it’s easy with a suction pump, but ideally you do it out of the water to get every bit out because it drains from the bottom. But if you are patient and flush some fresh oil through a couple times you can get it clean from the inside. If it’s an earlier model I don’t think you can do it in the water.
I’ve only had boats with sail drives. The one I have now is great though! Of course it’s brand new. They all seem to have one or more design flaws.

 

[Ralph Johnstone]

They all seem to have one or more design flaws.

Thanks for the explanation.

The only design flaw that scares me is that 13K one. I don't think it would hurt to attend church a few more times during the year either. A few extra coins in the poor box wouldn't hurt either. I know I would .

 

[Egovos]

Thanks for the explanation.

The only design flaw that scares me is that 13K one. I don't think it would hurt to attend church a few more times during the year either. A few extra coins in the poor box wouldn't hurt either. I know I would .

Yup, I think I’m going the certified mechanic route.
The sample was taken during the survey of the boat, right after the sea trial.
It’s an SD20 from 2014 and supposedly the engine has been serviced annually. I noticed that the tachometer wasn’t working so maybe there’s excessive wear on the gears.

 

[forbin]

It’s an SD20 from 2014 and supposedly the engine has been serviced annually. I noticed that the tachometer wasn’t working so maybe there’s excessive wear on the gears.

I don’t think you can change the gear oil on the 20 without taking it out of the water. Yanmar says 100 hours so depending on usage it may not have been changed as recommended. The previous owner would have to provide that info.

My tach was working intermittently, turns out the plug had jiggled loose on the back, so worth checking that too.

 

[Ralph Johnstone]

I noticed that the tachometer wasn’t working so maybe there’s excessive wear on the gears.

My tach was working intermittently, turns out the plug had jiggled loose on the back, so worth checking that too.

How do the (I'm guessing saildrive) gears influence the tach. Tachs normally sense from the flywheel or the alternator or with the newer VDO, a few additional points as well.

 

[Davidasailor26]

My tach was working intermittently, turns out the plug had jiggled loose on the back, so worth checking that too.

If it’s a 2014 Yanmar engine I’m guessing it’s a YM series engine? If so the tach is driven from alternator pulses, so not anything related to the gears. The tach issue could be caused by a bad tach itself, something in the wiring between the alternator and tach, or the alternator. If it’s intermittent my guess would be a flakey connection somewhere.

 

[forbin]

If so the tach is driven from alternator pulses, so not anything related to the gears.

My guess is he's thinking without the tach they could have been running the engine harder than they should have been and that that could have caused excessive wear on the gears. Based on my experience and previous comments, the owner probably did the engine service annually, but because with the SD20 a haul out is required to change the gear oil, that it was left longer than the recommended interval, depending on how they used the boat, and that's why the Fe came in high.

 

[Egovos]

My guess is he's thinking without the tach they could have been running the engine harder than they should have been and that that could have caused excessive wear on the gears. Based on my experience and previous comments, the owner probably did the engine service annually, but because with the SD20 a haul out is required to change the gear oil, that it was left longer than the recommended interval, depending on how they used the boat, and that's why the Fe came in high.

yes Forbin, that's exactly what I was thinking, that since the tach wasn't working maybe they drove the engine harder than recommended by Yanmar. I'm going to have a mechanic look at it just to be sure.

 

[Davidasailor26]

The 3YM series, whether with the SD or traditional transmission, is rated for continuous power of 3489 RPM and fuel stop power of 3600 RPM. I think it’s unlikely that the SD would’ve been damaged by overrunning the engine just from an intermittent tach. It’s also presumably a single shift/throttle lever, so unlikely that the gears could be damaged by shifting at high RPMs.

 

[Hayden Watson]

All that I know about this is that the more I learn about sail drives, the happier I am to have a shaft.

 

[FastOlson]

All that I know about this is that the more I learn about sail drives, the happier I am to have a shaft.

Absolutely!!!!
Sail drives do save money for the OEM builder, but after that maintenance costs to the subsequent owners are significant. Not a subject that comes up often at indoor boat shows in January, unfortunately.