Yanmar question

tfox2069 · Dec 15, 2023

Froman1950 said:
Hi,
I have a Saga 43 with a Yanmar diesel. I'm a very experienced sailor bot a new boat owner. Hope this question isn't too easy. I just learned that Yanmar engines have a sperate transmission fluid recepticle that must be drained separately from the engine oil. Is this true? Does it depend on whether the engine takes motor oil or ATF in the tranny box?
Thanks
Mike

A little confused by your question. You seem to indicate you understand there's two fluid reservoirs - one for the transmission and one for the engine. So yes, you'd need to drain and refill those two separate reservoirs with the appropriate (and likely different) fluids. For example, my 3YM30 had a Kanzaki transmission. The 3YM30 took Shell Rotella 15W-40 and the Kanzaki transmission took straight 30 weight oil. They're drained and filled in separate places. Even if they took the same oil, they are still in different places and lubricate separate functions, so you need to do both separately. I'll caveat all this by saying perhaps there's some model of Yanmar that does this differently, but I haven't seen it. You are also well served to get the manual for both the transmission and the engine and using those as a guide.

Capt. Jeff · Dec 15, 2023

To the best of my knowledge, Yanmar engines all have separate reservoirs.

Ralph Johnstone · Dec 15, 2023

Froman1950 said:
I have a Saga 43 with a Yanmar diesel.

Why not make this really easy for our members and give us a head start by telling us the model and year of your engine ?

Capt. Jeff said:
To the best of my knowledge, Yanmar engines all have separate reservoirs.

Further to @Capt. Jeff 's comment, I have never seen a Yanmar without separate reservoirs even when the fluid is the same in each. Think of your transmission running in road tar for lubrication.

kloudie1 · Dec 15, 2023

some of the "above 30 HP" Yanmars did take ATF the ticket is to look on the side of the transmission case .. there should be a metal tag that states the gear ratio, the model number, and the oil required .. The transmissions with ATF are model KBW.. and some other models.
Welcome aboard, Froman!
Go to "Owner Resources" then click on "General Downloads" Then scroll down to the Yanmar service manual stuff and click on your engine model..

dlochner · Dec 15, 2023

To the best of my knowledge, no engine and transmission share the same oil supply. Doesn't matter if it is a car, truck, train, or boat. The transmission and the engine are 2 separate components.

On the transmission there should be a plate with the transmission's model number, its gear ratio, and the type of lubrication, oil or ATF. If the transmission takes ATF, use ATF designed for older cars as the new ATFs, Dextron IV and above are too slippery for the clutches of older marine transmissions.

Stu Jackson · Dec 15, 2023

dlochner said:
To the best of my knowledge, no engine and transmission share the same oil supply. Doesn't matter if it is a car, truck, train, or boat. The transmission and the engine are 2 separate components.

Doesn't matter if you are an experienced sailor or not.

Being an experienced human would help a lot.

sailcapt340 · Dec 15, 2023

tfox2069 said:
A little confused by your question. You seem to indicate you understand there's two fluid reservoirs - one for the transmission and one for the engine. So yes, you'd need to drain and refill those two separate reservoirs with the appropriate (and likely different) fluids. For example, my 3YM30 had a Kanzaki transmission. The 3YM30 took Shell Rotella 15W-40 and the Kanzaki transmission took straight 30 weight oil. They're drained and filled in separate places. Even if they took the same oil, they are still in different places and lubricate separate functions, so you need to do both separately. I'll caveat all this by saying perhaps there's some model of Yanmar that does this differently, but I haven't seen it. You are also well served to get the manual for both the transmission and the engine and using those as a guide.

Same for my Yanmar 3GM30F. Two separate entities, transmission uses approximately 1 pint of 30W, engine about 4 quarts.

Davidasailor26 · Dec 16, 2023

Froman1950 said:
but I thought I read somewhere that some Yanmar diesel series engine use the same oil in the engine and the transmission.

Probably just an oversimplification from “some Yanmar engines use motor oil for both the engine and transmission”, but generally different weight, and definitely different reservoirs.

If you know the engine model it’s generally possible to find the manual online as a PDF. Always check the actual plates on the engine and transmission to confirm what a downloaded PDF says though.

sailme88 · Dec 16, 2023

NOT all ATF's are created equal. You NEED to ascertain the exact transmission that is mated to your engine. Once you KNOW for sure what the tranny is, then you can research the exact ATF to use. Using the wrong fluid is be as harmful at just plain neglect. There are also transmissions out there that are cooled on a closed loop off the raw water system. If there are hoses into and out of the tranny, follow them. Should they end at a sausage cooler ( small heat exchanger), you'll need to check this for glycol level AND pencil zinc on the raw end.

dlochner · Dec 16, 2023

The transmission dip stick does not look at all like the engines dipstick. On a Kanzaki transmission it is generally located on the aft port side of the transmission and looks like a bolt (17mm?). Do not screw the dipstick in to check the level. Place the end of the dipstick on a clean white paper towel to more easily see the fluid level. If it is red, the transmission takes ATF, if it is brown or amber, it is motor oil, if it is black the transmission needs to be rebuilt.

Draining the fluid is usually not easy, so use a vacuum pump and suck it out of the dipstick hole.

Tally Ho · Dec 16, 2023

As others have said, some Yanmar engines / transmission pairs use the same oil in the transmission and the engine uses…but they do not share the same oil.

My 2GM20 engine used 30wt oil in the engine. It is black as sin.
My Kanzaki KZ2P transmission also uses 30wt oil. But it has a separate reservoir.

You can just see the oil fill cap for the transmission…the yellow plug.

You might look for a similar plate on your trans to verify. As @dlochner said, if it is red, it is probably ATF, amber is probably oil (it should not get black like the engine oil).

Greg

jdrutten · Dec 16, 2023

This reminds me that I want to be sure to change my transmission oil before recommissioning in the spring. I previously followed the suggestion on p. 60 of the "Yanmar Diesel Inboard Shop Manual" to use 10W-30 with the Kanzaki KM2P. But like Greg noted above, my 2gm20f actually has a plate that calls for "SAE 20/30." I don't really understand the discrepancy, but will go with what's on the plate.

dlochner · Dec 16, 2023

dlochner said:
To the best of my knowledge, no engine and transmission share the same oil supply. Doesn't matter if it is a car, truck, train, or boat. The transmission and the engine are 2 separate components.

On the transmission there should be a plate with the transmission's model number, its gear ratio, and the type of lubrication, oil or ATF. If the transmission takes ATF, use ATF designed for older cars as the new ATFs, Dextron IV and above are too slippery for the clutches of older marine transmissions.

I misspoke. I do know of a diesel powered boat that does not have a transmission, The LT-5. It is the last or one of the last surviving tugboats used on D-Day. It is currently moored in Oswego, NY under the stewardship of the H Lee White Maritime Museum.

The LT-5 was designed to cross the Atlantic and then cross the English Channel to assist in the landing. She was armed with one machine gun and was credited with shooting down one plane.

The boat is a direct drive two stroke diesel. If you want to change direction, from forward to reverse, the engine was stopped and restarted with the engine rotation in the opposite direction. Makes docking kind of a challenge.

An interesting boat, here are a few links:

The LT-5, Major Elisha K. Henson

H. Lee White Maritime Museum at Oswego

hlwmm.org

Museum Report - The Large Tug That Fought

www.usni.org

kloudie1 · Dec 16, 2023

The only powerplants that I've encountered that shared transmission and engine oil were on motorcycles and a few cars..I know that Honda did that on many of their bikes back in the 60's-70's.. .. I had an MG 1100 sedan whose transmission and differential was in the oil pan of the engine.. I don't know of any heavy duty applications like boats that did that.. The viscosity of gear oil and transmission oil is pretty much the same.. Ninety wt gear oil sounds a lot different from 30 wt engine oil but if ya look at the vis specs, they are about the same.. a different numbering system is used on gear oil and it has a very different additive package, but their viscosity and lubricity are pretty much the same..

Stu Jackson · Dec 16, 2023

Froman1950 said:
but I thought I read somewhere that some Yanmar diesel series engine use the same oil in the engine and the transmission.

Davidasailor26 said:
Probably just an oversimplification from “some Yanmar engines use motor oil for both the engine and transmission”

Tally Ho said:
some Yanmar engines / transmission pairs use the same oil in the transmission and the engine uses…but they do not share the same oil.

These are all very interesting observations, which, once again, prove the difficulty and importance of using proper terminology and those pesky adjectives and adverbs. I was always lousy at grammar, couldn't do "foreign" languages worth a darn because of that, and became an engineer anyway! My middle name was Mr. Specificity and some colleagues called me The Professor because I became so exacting in reviewing their plans and, erm, specifications.

I can clearly see now how Froman1950 could have become confused win his first of these three ^^^ quotes. It's an example of inverted grammatical applications. It's like one of those examples: "All Xs are Y, but not all Ys are X." English is a funny language.

But the fact remains that, while identical oil could be used, the critical fact is that the engine oil and transmission oil always remain in separate reservoirs (except in kloudie's and Dave's unusual and singular examples).

Glad we could help clear that up for Froman1950.

jssailem · Dec 17, 2023

Froman1950 said:
I drain my engine oil with a pump down the fill tube, and wondered if in these engines the one operation got the oil in both reservoirs

Now that the 2 reservoirs are clear.
Welcome to the SBO forum. Congrats on new boat ownership. There is a lot to learn about systems and then sailing your own boat.

I highlighted your statement. I too use a vacuum pump to suck the engine oil out of the oil pan, in my case through the dipstick tube, not the fill tube. I can get 85% of the engine oil out. What I cannot get to is the oil in the cooler and hoses.

When the engine has warmed the crankcase oil it is a fairly basic task. Pump suck watch how much is extracted. Empty the 4 qt container and go back in for the last of the 5 qts.

In transmissions, this can be a bit more tricky, dependent on the maker and design. On my BorgWarner V-drive there is a reservoir beneath the fill tube. Then there is a second reservoir on the opposite side of the transmission. And finally there is a cooler filled with transmission oil. I learned all about these secondary pockets when I removed my transmission. To change the oil you will need to suck or blow out the fluids from places only accessible if you study the manual for your specific equipment. Or you can experiment, like I did, and remove the equipment. (Not recommended due to high probability of spilling oil into the bilge and everywhere else).

Good luck with your project.

arf145 · Dec 26, 2023

dlochner said:
To the best of my knowledge, no engine and transmission share the same oil supply. Doesn't matter if it is a car, truck, train, or boat. The transmission and the engine are 2 separate components.

Just for the record, many, possibly most, motorcycles share engine and transmission oil with one sump.