Yanmar saildrive - water leak management

[GrahamHO]

Originally Posted by arsenelupiga

for the record:

i have pumped out saildrive oil in both legs to see any traces of water. Helps against slipping as well.

After 3 weeks, I found around 3 cm3 of water on bottom of bottle from port saildrive. Oil was changed after 20 min motoring.

This leads to strategy how to live with water in saidrives till next slip.

Motor for at least 20 min every week.

this way water will remain trapped by oil and no corrosion.

Anyone similar experience ?

Yes! As I've already mentioned; Mercury Quicksilver stern drive oil is supposed to be the most water tolerant of suitable oils. There are two qualities and the more expensive is meant to be the better, of course. I forget its designation. It should not be mixed with ordinary oils, though if you drain the old and let it drip for a while there is no problem in my experience.

The Yanmar shaft wears where it contacts the seals. There is a standard fix to build up that area with a harder metal and grind it back to the right diameter. I think they use hard chrome. I had that done several years ago and have never had a problem since. Of course replace the seals at the same time.

You should be fine for a while using Quicksilver oil and changing it when possible. But the oil is expensive and the repair not very expensive and was done within 2 days for me. I think the Mercury oil must necessarily be good as it is very very common to see Mercury Stern Drives having seals replaced on hard stands. They don't like fishing lines. The Yanmar seal is fairly well protected from fishing lines.

[arsenelupiga]

Originally Posted by NoTies

20 cm above the waterline??? Where's the engine, in the cockpit?

well, I have cat with large engine room. And not heavily loaded. I am pretty large and can do things around motor.

Seacock does not have to be closed ever as it is above water line. Have proven it by removing hose and not closing seacock! Oil level is another 15 cm higher.

I also learned that I do not have to close seacock when changing impeller. So it is really easy operation. Also changing saidrive oil is really easy in water.

[arsenelupiga]

Originally Posted by GrahamHO

Yes! As I've already mentioned; Mercury Quicksilver stern drive oil is supposed to be the most water tolerant of suitable oils. There are two qualities and the more expensive is meant to be the better, of course. I forget its designation. It should not be mixed with ordinary oils, though if you drain the old and let it drip for a while there is no problem in my experience.

The Yanmar shaft wears where it contacts the seals. There is a standard fix to build up that area with a harder metal and grind it back to the right diameter. I think they use hard chrome. I had that done several years ago and have never had a problem since. Of course replace the seals at the same time.

You should be fine for a while using Quicksilver oil and changing it when possible. But the oil is expensive and the repair not very expensive and was done within 2 days for me. I think the Mercury oil must necessarily be good as it is very very common to see Mercury Stern Drives having seals replaced on hard stands. They don't like fishing lines. The Yanmar seal is fairly well protected from fishing lines.

thanks for hints & will have a look when get a chance. I just wanted to prove it to distinguish good info from suburbia legends. Oil change costs $30 & 1/2 hour, not such a big deal. I can get it 1.8L out.

[NoTies]

Originally Posted by arsenelupiga

well, I have cat with large engine room. And not heavily loaded. I am pretty large and can do things around motor.

Seacock does not have to be closed ever as it is above water line. Have proven it by removing hose and not closing seacock! Oil level is another 15 cm higher.

I also learned that I do not have to close seacock when changing impeller. So it is really easy operation. Also changing saidrive oil is really easy in water.

I'm trying to get my head around this. The seacock which, from memory is around 5 cm above the rubber boot is above the waterline? Do you have any cavitation issues when punching to windward?
Anyway, install a reservoir as high as possible to keep positive pressure within the sterndrive.

[DotDun]

Originally Posted by NoTies

I'm trying to get my head around this. The seacock which, from memory is around 5 cm above the rubber boot is above the waterline? Do you have any cavitation issues when punching to windward?
Anyway, install a reservoir as high as possible to keep positive pressure within the sterndrive.

He must be talking about a different seacock as part of or at the strainer. Opening the strainer would allow for not having to close the seacock when changing the impeller.

[arsenelupiga]

Originally Posted by DotDun

He must be talking about a different seacock as part of or at the strainer. Opening the strainer would allow for not having to close the seacock when changing the impeller.

I am talking about my frozen seacock in SD 50. See pic. I only undo impeller and change. Pipes are cleverly positioned so that no other action required. I got motor spitting water in 2 seconds after change. You have to keep pipe from strainer to impeller in correct position though else water escapes.

[arsenelupiga]

Originally Posted by NoTies

I'm trying to get my head around this. The seacock which, from memory is around 5 cm above the rubber boot is above the waterline? Do you have any cavitation issues when punching to windward?
Anyway, install a reservoir as high as possible to keep positive pressure within the sterndrive.

Above waterline - removed pipe from it and no water comes out and it as open frozen. Has no useful function so will not bother changing it. I am physicist by profession and always look for better way to do things.

Hull at max point is around 70 cm under water. another 50 are mini keels. Propeller is around 60 cm below water line, maybe less. There is bit of cavitation in when beating but nothing out of ordinary. Even at large chop stern of boat is surprisingly little movement as it has large buoyancy.

[DotDun]

Originally Posted by arsenelupiga

I am talking about my frozen seacock in SD 50. See pic. I only undo impeller and change. Pipes are cleverly positioned so that no other action required. I got motor spitting water in 2 seconds after change. You have to keep pipe from strainer to impeller in correct position though else water escapes.

Is your raw water pump above the waterline?

If not, you have a potential to syphon water thru the strainer when opening the pump without closing a seacock.

[arsenelupiga]

Originally Posted by DotDun

Is your raw water pump above the waterline?

If not, you have a potential to syphon water thru the strainer when opening the pump without closing a seacock.

it is above water line. Pipe from strainer to impeller is long and reaches at middle below water line level. This allows seacock to be ignored when changing impeller.

Only when cleaning strainer is required to close. But that is not expected to be too often so will not bother fixing frozen seacock.

[monte]

This link might be helpful
http://hackingfamily.com/Cruise_Info...SailDrives.htm

[arsenelupiga]

Originally Posted by monte

This link might be helpful
Sail Drives

i get that completely. but so far I am yet to detect any pressure immediately after turning off engines. When opening saildrive dipstick, oil goes out slowly like when milk boiling. No pressure. If pressure, there should be pop or oil bursting out.

All evidence I have so far, is that this setup is already built in SD 50 installation so nothing to do.

I verified that actually there is no water. Something was on the bottom of old oil saildrive bottle and I assumed is water. I have turned bottle around, left couple of days, and opened so whatever was at bottom came out. Seem only darker oil and no traces of water.

As taking out boat is 3k in sydney and new SD 60 is 5-6k, I will not take boat out to change seals except when due for service. Oil changes seem quite good temporary measure, when needed.

[dmccoy]

Originally Posted by Captain Bill

Item 3 is a real possibility and a problem. It happened to me. I had to use high power for about 20 minutes once (Max. Cont.) and it boiled the water in the drive leg. There was only a small amount of water in the oil at the time, just a little milky, not looking like a chocolate milkshake. It inverted every seal in the drive and blew out all of the oil. It instantly filled with seawater. By the time I got it hauled the drive required a complete overhaul to the tune of about $6K by the time yard fees were included. If you can be sure that you'll never need to use high power, you can take a chance. The drive oil I used advertised that it contained an emulsifying agent that was supposed to protect the metal if contaminated with water. It didn't help a bit after it was blown all over my engine room by the water turning to steam. Then again maybe your oil doesn't have such an agent and the seawater can start corroding the bearing right away.

What do you mean by "suspicion" ? There is either water in the oil or there's not. If there is, my advice is to haul the boat and have it repaired. Changing the prop shaft seals takes about an hour to an hour and a half. The seals cost about $125 US, If you have the parts, (oil Seal, water seal and two O-rings) It should take no more than three hours labor to do both drives. I did both of mine myself, including the complete reassembly of two autostream feathering props in 4 hours. I don't know what the going rate for a haul out in Sydney is, but I did the whole job for about $1000 including the haul out.

One other item is that yanmar uses cheap unhardened steel in their prop shafts and the oil seals wear grooves in them. At some point they will no longer seal and you'll need a new shaft. It's possible to have the old shaft turned down a few thousandths and have a chrome steel sleeve put on the shaft. I had this done about 4 years ago.

Also do both drives even if there's only oil in one!


Good luck, and if there's water in the oil do not use high power.

Yeah, I'm at the point where I think I need to replace the prop shaft on my SD-60. They're $900 though! Do you recommend the approach you took milling your old shaft and adding a harder sleave? How much did that cost to do?

[Captain Bill]

Originally Posted by dmccoy

Yeah, I'm at the point where I think I need to replace the prop shaft on my SD-60. They're $900 though! Do you recommend the approach you took milling your old shaft and adding a harder sleave? How much did that cost to do?

It was a while ago but I think the sleeving procedure cost me less than $200 each. I traded my SD40s for sd60s in 2015 so I can't say for sure how long it would have held up. I had the procedure done in Dec. of 2011 so at least 3 years. I'm glad to hear that yanmar is now selling new shafts for sd60s. When I looked at the parts manual in 2017 the only way to get a new shaft was to buy a whole lower unit to the tune of $5600. It was pretty close to the cost of a new saildrive. I'ld give the sleeving procedure a try.

[Moontide]

Had one sleeved in Trinidad 4 years ago and it was not very expensive at all. Mechanic I was using to help install a new engine knew about the issue and had a machine shop do it.

Has not been an issue since.


Bill