Yanmar SD40 & SD50 "slipping" Saildrive Upgrade

[Bruce Beard]

Originally Posted by Tornadosailing

Ok this got me thinking. The wrong fluid theory is much more plausible than the assumption I made that it was incorrect tolerances due to copper shim wear.

So would we be better off going with a fluid that was specifically formulated for bronze syncronizers? How about GM Synchromesh fluid? I know it helps in old manual transmissions. Why not here? After all, this thing is simply an inverted syncronizer.

Correct... sort of...
it is like a synchronizer and it is bronze.
The “thinking” is actually already done once you understand that you are trying to protect the friction drive. A GL-4 gear oil is exactly what you want. With the knowledge that a GL-5 that “meets or exceeds” GL-4 is exactly what you do not want!!!!
There are good synthetic and mineral based GL-4 gear oils out there of the correct viscosity (I have forgotten the recommended viscosity as we have gone to the dark side now...) that will work perfectly.
You have to look at the API ratings and discern the difference.

[arsenelupiga]

Originally Posted by Bruce Beard

Correct... sort of...
it is like a synchronizer and it is bronze.
The “thinking” is actually already done once you understand that you are trying to protect the friction drive. A GL-4 gear oil is exactly what you want. With the knowledge that a GL-5 that “meets or exceeds” GL-4 is exactly what you do not want!!!!
There are good synthetic and mineral based GL-4 gear oils out there of the correct viscosity (I have forgotten the recommended viscosity as we have gone to the dark side now...) that will work perfectly.
You have to look at the API ratings and discern the difference.

reading thru manual, what you suggest is recommended for GM, YM type of engines. For JH3,JH4 and JH5 type of saildrives SD50 and SD50-4T saildrive oil is quicksliver.

Presume yanmar is aware of what you say, yet they are very strict in manual what oil to use. I tend to follow manufacturer manual when conflicting info.

[Bruce Beard]

Originally Posted by arsenelupiga

reading thru manual, what you suggest is recommended for GM, YM type of engines. For JH3,JH4 and JH5 type of saildrives SD50 and SD50-4T saildrive oil is quicksliver.

Presume yanmar is aware of what you say, yet they are very strict in manual what oil to use. I tend to follow manufacturer manual when conflicting info.

I too, default to manufacturers specifications. If it helps, Yanmar says that both GL-4 and GL-5 is approved for use in an SD-50. The use of both is the clue to there being something amiss. Think of it this way, if only if you can use a GL-4, you have no need of a GL-5 and if you need a GL-5 a GL-4 won’t work. My saildrive had decals declaring use of either GL-4 or GL-5 was acceptable. That was the first clue to a problem.

If you read the manual that came with my saildrive in 2005 it clearly specified that either standard was sufficient. After using the GL-5 for 2 seasons and destroying the drive I switched to GL-4, still a specified oil and had no further issues.
My engine was a 3jh4e...


Bruce

[Tornadosailing]

Originally Posted by Bruce Beard

Correct... sort of...
it is like a synchronizer and it is bronze.
The “thinking” is actually already done once you understand that you are trying to protect the friction drive. A GL-4 gear oil is exactly what you want. With the knowledge that a GL-5 that “meets or exceeds” GL-4 is exactly what you do not want!!!!
There are good synthetic and mineral based GL-4 gear oils out there of the correct viscosity (I have forgotten the recommended viscosity as we have gone to the dark side now...) that will work perfectly.
You have to look at the API ratings and discern the difference.

Synchromesh is GL-4 with friction modifiers formulated for bronze synchronizers.

[Bruce Beard]

Originally Posted by Tornadosailing

Synchromesh is GL-4 with friction modifiers formulated for bronze synchronizers.

Then it should be fine. One way to know if the oil you are using is working well is that once drained, the correct oil doesn’t have the bronze sheen that a GL-5 oil has. Our oil would come out after about 200 hours, a typical season for us, and look almost new. After a season with the Mercury Quicksilver oil that Yanmar recommended, the oil looked like it contained a swirl of bronze paint.
Bruce

[ChrisseH]

Thanks Bruce and others for the input.

Had already purchased some Quicksilver gear-lube, but luckily still not changed the oil in my SD50 (the yacht is still on the hard). Since I lapped the cones last year I have been using the engine for 180 hours, of which perhaps 30 for charging/hot water. And yet I have not observed any new slipping.

The question is now what type of API GL-4 I should use instead? Cannot find Syncromesh locally here in Finland. Have been googling and noticed that many of the GL-4 80W-90 gear-lubes are EP marked. As Bruce pointed out gear oils include (in additional to mineral or synthetic oil) viscosity improving substances, but often also EP additives. As far as I have learned EP stands for EXTREME PRESSURE which in other words means extreme gear pressure or loads. The EP additives include typically Sulfur and Phosphorus compounds that prevent "welding" and wear of the gear teeth.

According to a Swedish site Sulfur-containing additives can attack brass or other Copper-containing alloys, so EP marked oils should therefore never be used in transmissions where, for example, the sync rings are made of brass. This is in line with what Bruce said, but now specifically related to the EP marking that some of the GL-4 oils have.

Bruce is right in that we ultimately can judge the oil by looking at the color, but I would obviously prefer to select the correct gear-lube immediately in order to avoid further wear. There are many brands on the market, but thought that the best would be if the oil would be of a brand that is easily available everywhere. I have therefore looked at the following four alternatives:

1) YANMAR genuine gear oil SAE 80W-90 - http://www.yanmarmarine.com/theme/ya...SAE-80W-90.pdf

2) Mobilube GX 80W-90 - http://www.ulei-mobil.ro/pdf/MobilAu...80w-90_140.pdf

3) Castrol Manual GL-4 80W-90 - https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/28E2A12E8DFE651280257CB6003F99C9/$File/KRAE-9J2FLR.pdf

4) Honda Gear Oil SAE90 GL-4 - Honda Marine Outboard Gear Oil SAE 90 GL4 1L - Pacermarine

It would certainly make sense to use Yanmar's gear oil, but is it really GL-4? Cannot find this classification in the data sheet.

And what about alternatives 2, 3 or 4? Any other commonly available gear-lube brands?

Christer

[Steven UK]

Sometimes you just stumble onto an awesome thread, I think this thread just solved two problems I’m having... thanks guys.

[Bruce Beard]

Originally Posted by ChrisseH

Thanks Bruce and others for the input.

Had already purchased some Quicksilver gear-lube, but luckily still not changed the oil in my SD50 (the yacht is still on the hard). Since I lapped the cones last year I have been using the engine for 180 hours, of which perhaps 30 for charging/hot water. And yet I have not observed any new slipping.

The question is now what type of API GL-4 I should use instead? Cannot find Syncromesh locally here in Finland. Have been googling and noticed that many of the GL-4 80W-90 gear-lubes are EP marked. As Bruce pointed out gear oils include (in additional to mineral or synthetic oil) viscosity improving substances, but often also EP additives. As far as I have learned EP stands for EXTREME PRESSURE which in other words means extreme gear pressure or loads. The EP additives include typically Sulfur and Phosphorus compounds that prevent "welding" and wear of the gear teeth.

According to a Swedish site Sulfur-containing additives can attack brass or other Copper-containing alloys, so EP marked oils should therefore never be used in transmissions where, for example, the sync rings are made of brass. This is in line with what Bruce said, but now specifically related to the EP marking that some of the GL-4 oils have.

Bruce is right in that we ultimately can judge the oil by looking at the color, but I would obviously prefer to select the correct gear-lube immediately in order to avoid further wear. There are many brands on the market, but thought that the best would be if the oil would be of a brand that is easily available everywhere. I have therefore looked at the following four alternatives:

1) YANMAR genuine gear oil SAE 80W-90 - http://www.yanmarmarine.com/theme/ya...SAE-80W-90.pdf

2) Mobilube GX 80W-90 - http://www.ulei-mobil.ro/pdf/MobilAu...80w-90_140.pdf

3) Castrol Manual GL-4 80W-90 - https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/28E2A12E8DFE651280257CB6003F99C9/$File/KRAE-9J2FLR.pdf

4) Honda Gear Oil SAE90 GL-4 - Honda Marine Outboard Gear Oil SAE 90 GL4 1L - Pacermarine

It would certainly make sense to use Yanmar's gear oil, but is it really GL-4? Cannot find this classification in the data sheet.

And what about alternatives 2, 3 or 4? Any other commonly available gear-lube brands?

Christer

So, I believe that you are misunderstanding the EP rating. All gear oil with the exception of GL-1 has some EP (sulfur) additive as part of its package.
The difference is the amount or volume needed to achieve the desired rating. You (at least I...) can smell the difference in a GL-4 and a GL-5 oil. The sulphur smell is much more pungent in a GL-5. It still exists in a GL-4 though...
The last sentence in the first paragraph of this Wikipedia article explains this better than I can... https://en.wikipedia.org/wiki/Gear_oil

I would look for an oil with the same viscosity that simply carries a true GL-4 rating without mentioning GL-5. You will be good to go!

By the way, if you lapped that cone as a result of slipping, think about replacing it sooner than later, especially if you have been using a GL-5 rated oil. The other thing I'd recommend is to change the new oil after a short time, just to get the last dregs of the old stuff gone. Oil is relatively inexpensive.

One final thought, I would not trust Yanmar for the oil as they were not aware of the issue themselves...they may have a perfectly suitable GL-4 but better safe than sorry...

Bruce

[Tornadosailing]

On my way to the boat Thursday to head to the Bahamas for a week. Just ordered 5 quarts Synchromesh to change the fluid before I go. Thanks Bruce!

[Bruce Beard]

Originally Posted by Tornadosailing

On my way to the boat Thursday to head to the Bahamas for a week. Just ordered 5 quarts Synchromesh to change the fluid before I go. Thanks Bruce!

Again,
Our first SD-50 failed in some 500 hours.
After replacing it and taking it apart, I switched to GL-4 oils for lube and never looked back. I did replace cone clutches as a precaution but never for slippage and I began extending the number of hours between changes because they looked so good. I remember not being to tell the difference in a new part and the one being replaced the last swap and I think that we'd put some 800 hours on the old one that time. Thankfully I'd marked the new cone with an indelible marker...

We traded the boat in with something like 2000 hours on the new drive and there were no problems. I had to reseal the lower unit after 6 or so years and the lower bevel gears looked new, they are not a hypoid type so I didn't expect problems anyway...
Good luck!
Bruce

[Bruce Beard]

Here is a photo of the 3JH4e engine in our Sabre at 10 years of age and some 1700 plus hours. I spent my working life in the business of European automobile repair and I am something of a maintenance freak...
Somehow, I have not kept sail drive photos...sorry.
Bruce

[Bruce Beard]

One more picture of the new boat and I'll be quiet...
We are truly enjoying the "dark side"!
Bruce

[RoadRacer]

^^^ Beautiful boat^^^
Thanks for sharing great information!

[ChrisseH]

Originally Posted by Bruce Beard

So, I believe that you are misunderstanding the EP rating. All gear oil with the exception of GL-1 has some EP (sulfur) additive as part of its package.
The difference is the amount or volume needed to achieve the desired rating. You (at least I...) can smell the difference in a GL-4 and a GL-5 oil. The sulphur smell is much more pungent in a GL-5. It still exists in a GL-4 though...
The last sentence in the first paragraph of this Wikipedia article explains this better than I can... https://en.wikipedia.org/wiki/Gear_oil

I would look for an oil with the same viscosity that simply carries a true GL-4 rating without mentioning GL-5. You will be good to go!

By the way, if you lapped that cone as a result of slipping, think about replacing it sooner than later, especially if you have been using a GL-5 rated oil. The other thing I'd recommend is to change the new oil after a short time, just to get the last dregs of the old stuff gone. Oil is relatively inexpensive.

One final thought, I would not trust Yanmar for the oil as they were not aware of the issue themselves...they may have a perfectly suitable GL-4 but better safe than sorry...

Bruce

Thanks again Bruce,

Not sure I can smell the difference between GL-4 and GL-5.

Had in mind to use the current cone as long as I can. Am not doing any long distance sailing and if/when the clutch starts to slip I can still use the drive for a while. The clutch will still engage, but not until you give enough throttle. Also, as I am mainly sailing I can always sail close to the harbor, drop the sails and reverse into the dock. But you are right in that the clutch sooner or later will start to slip.

Unless there are no strong arguments against, I will probably now try the Mobilube GX 80W-90.

Christer

[kenckar]

This is a video of the cone lapping repair on an SD50. IT doesn't show the more permanent repair, but it's good to watch.

https://www.youtube.com/watch?v=M4EwhbRHvvE

By the way, that's my boat, and the guy doing the work is Evan Macaluso out of Houston.

Seeing this video really helped me understand what the issue is.