Oil for Kanzaki Marine Gear/Yanmar

[Dockhead]

Time to change the gearbox oil again, and once again I'm stumped on what oil to use. Yanmar requires both motor and gearbox oil which is hard to find.


For the motor (4JH3 HTE), I finally decided to stop beating my head against the wall and finally now just use the Yanmar oil, which isn't actually that much more expensive than anything else.


But what about the marine gear? The manual says straight 20W or straight 30W, and I've read cautions to never use multiviscosity and to avoid HD if possible. So where do you get straight, non-HD 30W?



What about lawnmower oil?



https://www.amazon.de/-/en/Briggs-St...%2C242&sr=8-18


or this:


https://www.amazon.de/-/en/Liqui-Mol...42&sr=8-5&th=1


Thoughts?

[Wotname]

Yep, SAE 30 oil is just a plain old single weight engine oil and it used by many many small engines in lawnmowers, mini yard tractors and the like. It should be available in any small engine shop.

It has been used in Kanzaki Marine Gear box for yonks.

[Dockhead]

Originally Posted by Wotname

. . . It has been used in Kanzaki Marine Gear box for yonks.

So others are using this? Great!

[skipperpete]

It’s important to know what NOT to use, last time my 4wd was serviced the mechanic used the fully synthetic version of the oil my manual transmission normally uses and I lost synchro on definitely first gear, mostly on second gear and less importantly on the rest, this applies until the gearbox warms up enough to allow the synchro’s to work better but first gear requires a full stop to engage. Next oil change I’m going back to the OEM oil and am ok with no synchro…. No gear crunches , just a refusal of the synchro’s to allow the required spin up of the gear to….Synchronize. This works against you with a marine clutch where you really want that cone or clutch plate pack to stick, not slip…. But not stick hard enough to resist disengaging or hard shifting. Into gear….. avoid fully synthetic oils!
On the “Liquimoly” link, be careful with which one of the range of oils you get , the liquimoly oils have as the name suggests, Molybdenum disulphide as an additive in some of their lube oils. I use almost exactly that oil in Dockheads link to try and squeeze another 100,000 miles out of my other car, a Pajero V6 with hydraulic tappets that sound like castanets ( this is in Malaysia). My point is that the moly 40 and the NON moly 40 is in very similar containers and even a tiny amount of a friction modifier like Moly will cause the marine clutch to slip.
Only plain old SAE 30 or 40 MINERAL oil ….., don’t be lured into synthetic or friction modified.

[Dockhead]

Originally Posted by skipperpete

It’s important to know what NOT to use, last time my 4wd was serviced the mechanic used the fully synthetic version of the oil my manual transmission normally uses and I lost synchro on definitely first gear, mostly on second gear and less importantly on the rest, this applies until the gearbox warms up enough to allow the synchro’s to work better but first gear requires a full stop to engage. Next oil change I’m going back to the OEM oil and am ok with no synchro…. No gear crunches , just a refusal of the synchro’s to allow the required spin up of the gear to….Synchronize. This works against you with a marine clutch where you really want that cone or clutch plate pack to stick, not slip…. But not stick hard enough to resist disengaging or hard shifting. Into gear….. avoid fully synthetic oils!
On the “Liquimoly” link, be careful with which one of the range of oils you get , the liquimoly oils have as the name suggests, Molybdenum disulphide as an additive in some of their lube oils. I use almost exactly that oil in Dockheads link to try and squeeze another 100,000 miles out of my other car, a Pajero V6 with hydraulic tappets that sound like castanets ( this is in Malaysia). My point is that the moly 40 and the NON moly 40 is in very similar containers and even a tiny amount of a friction modifier like Moly will cause the marine clutch to slip.
Only plain old SAE 30 or 40 MINERAL oil ….., don’t be lured into synthetic or friction modified.

Thanks for that. Yes, I have been aware since I've owned boats that synthetic oil can be poison to older diesel engines. I've linked the classic article on this by Vyv Cox and will link it again for the benefit of newer members here: Oil for yacht engines – Cox Engineering. Vyv is a yachtsman AND a petroleum engineer so this is an invaluable resource (the rest of his site is packed full of good stuff, too).


I'll double check the Liqui Moly and if there's any doubt I'll go with the Briggs and Stratton.


Liqui Moly also make a CLASSIC branded straight 30W, which I believe has no detergent, so suitable for old motorcycle engines without oil filters. But Yanmar specify HD, so I don't think I'll do that one.

[Wotname]

Interesting conflict here - the plate clearly shows SAE20/30HD while my Yanmar service manual calls for SAE20/30. Neither shows what API spec is required. See screenshot.

What is HD? That depends on who you ask, it can mean High Detergent or it can mean Heavy Duty. Back in the day (say 1950s) oils were light and simple. At some time, API specs were introduced and a spec of API CD was considered 'heavy duty'. All small Yanmar engines up to the GM series were specified with SAE 30, API CD. Many of the Kanzaki gear boxes called for using the oil as the engine, i.e. SAE30 API CD.

What should DH use? I dunno but I think there is more evidence suggesting that the KMA4A needs SAE30 API CD or better.

AFAIK, high detergent oils should not be used where there is no oil filter. I.E. a high detergent oil is not appropriate for the KMA4A but a 'heavy duty' oil is and any API spec of CD or later is a 'heavy duty' oil by the older use of terminology - but I could be wrong...

[Dockhead]

Originally Posted by Wotname

Interesting conflict here - the plate clearly shows SAE20/30HD while my Yanmar service manual calls for SAE20/30. Neither shows what API spec is required. See screenshot.

What is HD? That depends on who you ask, it can mean High Detergent or it can mean Heavy Duty. Back in the day (say 1950s) oils were light and simple. At some time, API specs were introduced and a spec of API CD was considered 'heavy duty'. All small Yanmar engines up to the GM series were specified with SAE 30, API CD. Many of the Kanzaki gear boxes called for using the oil as the engine, i.e. SAE30 API CD.

What should DH use? I dunno but I think there is more evidence suggesting that the KMA4A needs SAE30 API CD or better.

AFAIK, high detergent oils should not be used where there is no oil filter. I.E. a high detergent oil is not appropriate for the KMA4A but a 'heavy duty' oil is and any API spec of CD or later is a 'heavy duty' oil by the older use of terminology - but I could be wrong...

Sigh.


Maybe just better to do what I did with my engine oil -- just buy the Yanmar stuff. Do they even sell oil for their gearboxes?

[cram]

HD30 (heavy duty) is available at most auto parts stores.... even Walmart has it.

[Wotname]

OK, it took a while but I have found the documentary evidence to support my earlier claim that you need single weight mineral oil - SAE 20 or 30 with an API specification of CD (or higher e.g. CE etc)

You have a 4JH3 with a KM4A gearbox.

I have Kanzaki / Yanmar manual for the KM4A, KM35A, KM35P boxes (plus others).
That manual specs SAE#20/30 (without multi-grade oil) for all of these gear boxes. That translate as 'single weight' SAE 20 or SAE 30.

I also have a Yanmar 4JH4 operations manual. Note the 4JH4 can be fitted with the KM35A, KM35P, KM4A1 & KM4A gear boxes. That manual specifies SAE#20 or SAE#30 with an API Service Categories CD or higher for these boxes.

If the Kanzaki manual specs SAE#30 oil for the KM35A & KM35P & KM4A and the Yanmar manual specs the SAE#30 (API CD) oil for the KM35A & KM35P & KM4A1, then it is pretty obvious the KM4A also needs SAE#30 (API CD) oil.

See screenshots.

[Alan Mighty]

Originally Posted by Dockhead

Maybe just better to do what I did with my engine oil -- just buy the Yanmar stuff. Do they even sell oil for their gearboxes?

Depends on the jurisdiction in which you are. Engine oil, lube oil. Same thing, lah.

[Wotname]

Originally Posted by Alan Mighty

Depends on the jurisdiction in which you are. Engine oil, lube oil. Same thing, lah.

Err...no.
Engine oil is a type of lube oil.
Marine Gear [box]oil is a type of lube oil.

However in DH's 4JH3, engine oil is not the same as marine gear [box] oil.

The manual calls for an engine oil spec of SAE 15W40, API CD and a marine gear [box] oil spec SAE 20 or SAE 30, API CD. See screenshot

However in some models, the engine oil is the same as gear box oil.

[Dockhead]

Thanks, guys. I think I will go with the lawnmower oil. I'll post about how it goes.

[Ericson38]

I use Yanmar HD30 single grade in my 4JH2-HTE and the same in the KM4A.

[Ericson38]

Originally Posted by Wotname

Interesting conflict here - the plate clearly shows SAE20/30HD while my Yanmar service manual calls for SAE20/30. Neither shows what API spec is required. See screenshot.

What is HD? That depends on who you ask, it can mean High Detergent or it can mean Heavy Duty. Back in the day (say 1950s) oils were light and simple. At some time, API specs were introduced and a spec of API CD was considered 'heavy duty'. All small Yanmar engines up to the GM series were specified with SAE 30, API CD. Many of the Kanzaki gear boxes called for using the oil as the engine, i.e. SAE30 API CD.

What should DH use? I dunno but I think there is more evidence suggesting that the KMA4A needs SAE30 API CD or better.

AFAIK, high detergent oils should not be used where there is no oil filter. I.E. a high detergent oil is not appropriate for the KMA4A but a 'heavy duty' oil is and any API spec of CD or later is a 'heavy duty' oil by the older use of terminology - but I could be wrong...

If you look at the image that was posted by Dockhead, the KM4A takes 1.3 liters, not 2.3 liters as the table specifies. I can't get 2.3 liters in mine without seriously overfilling it, if I go by the dipstick.

https://www.cruisersforum.com/forums...ml#post3902489

[GordMay]

Q: What do you call motor oil from Cuba?
A: Fidel Castrol.