yanmar 4JH3-TE engine with KM4A clutch use original oil?

[Izikalvo]

I have the above setup
my oil touches the deep stick but below the line, do i have enough oil?

can i use any automatic gear transmission oil to fill up or only use the OEM one?

thanks

[Captsteve53]

The Yanmar KM4A clutch(transmission) from there own specification says to use SAE#20 OR SAE # 30 mono grade engine oil,

Personally i would go with the SAE # 30 grade , do not use 15/30 10/30, as these are not mono grade oils ,

Any reputable brand mono grade oil can be used such as Shell/Mobil/Caltex etc

The oil should come up to the mark on the dipstick, and to note these clutch (transmissions) arrangements only hold 1.3 liters.

Cheers Steve

[Izikalvo]

you mean mono grade transmission oil not engine oil right?

thanks

[Quebramar]

Yes that's right. I just changed mine and the technician explained me that people used to put engine oil, yet more recently it appeared that multigrade oil has additives that may damage the mechanic. 30 is what Yanmar sells today

[Captsteve53]

Normal SAE Engine oil , just not multi grade, Actually this is very common with numerous engine transmission combinations these days,

[Captsteve53]

Gear oils really only start @ in the normal range SAE 68 through 140/160 and then EP range can go up to 600-800,

Cheers Steve

[Izikalvo]

the thing is that I changed my trans oil with the OEM Yanmar oil and it comes in a one-liter bottle and as you mentioned it needs 1.3 letters. can I add another kind of oil with the Yanmar oil? maybe it is better to add regular car transmission oil?

[Captsteve53]

The original Yanmar trans lube oil will be a regular SAE ENGINE OIL either mono 20 grade or mono 30 grade (may show on the bottle) with a Yanmar bottle or Yanmar sticker on it, But again nothing special just an Engine grade oil purchased from one of the large suppliers with their bottle/name and charge you more for it!!

Do not put ATF OR AUTO-TRANS fluid in these Yanmar transmissions as failure will occur sooner or later,

Normally I dont recommend mixing oils (brands or viscosity) and prefer to drain and fill with the same oil in a workshop environment, that said how many people stick with one brand of oil when topping up around the world with engines,or transmissions as long as the viscosity is correct they normally accept what they can get at the time and suffer no consequences.

If it were mine and couldn't find another bottle of Yanmar lube I would top off with SAE 30 Engine oil and have a nice day

PS: I have been a chief commercial maritime engineer for some 30 plus years so advice not coming from an arm chair driver

Cheers Steve

[S/V Alchemy]

Originally Posted by Captsteve53

Normal SAE Engine oil , just not multi grade, Actually this is very common with numerous engine transmission combinations these days,

Sometimes called "straight 30" or "straight 30 weight", it's also the preferred grade for the common block and transmission sump for Atomic 4s. I never had real trouble finding it, but sometimes I had to ask as 90% of the oil sold is 10W30 or 15W40 for diesels.

[Izikalvo]

thank you all you have been a great help

[Alita49DS]

You don't have to be a marine engineer. An armchair will do fine as this is a simple case of RTFM. If you do not know what that stands for then, as a clue, the first letter stands for Read and the last Manual.

The manual, I have the same engine, clearly states: -

NOTICE:
Using other than the specified lube oil will lead to seizure of parts inside the engine and gear device , abnormal wear, and shorten engine life. It will also effect the starting ability and power output.
(2) Marine Gear Oil and sail-drive oil
Be sure to use the following lube oil for the marine gear and the sailing boat drive.
• KBW21
Converter oil for automobiles ATF
• KM4A, KMH4A
API Classification..............CC or higher
SAE Viscosity....................#20 or #30(not available multi grade)
• SD40-4T
Refer to the operation manual for the sail drive.
(3) Handling the Lube Oil
• When handling and storing lube oil, be careful not to allow dust and water to enter the lube oil.
Clean around the filler port before refilling.
• Do not mix lube oils of different types or brands.
Mixing may reduce the lubricating performance. Different oils are used for the engine and the marine gear.
Be careful to use the correct oil for each one and store in separate clearly labelled

containers.

You need to hop around the manual a bit to find things but they are all there. You can download the manual.

My over 30 years experience with boats has mainly been getting it wrong because I did not spend time in an armchair RTFM. Likewise, my experience with so called experts, from plumbers upwards, has been their screwing up at my expense because they thought their experience exempted them from RTFM!

[Captsteve53]

Give you two guesses who designed and wrote the input for the Engine/transmission?

A) An armchair driver

B) Professional Engineer

Note: Armchair drivers have been known to get this wrong!!

[Alita49DS]

Sadly, and with the greatest possible respect to you, I think that you miss the point.

(B) The genuinely professional engineers who designed the engine and transmission will have specified the maintenance schedule. The word "professional" has been debased, along with others such as "officer" in modern western society. Where the aim appears to be to give the office cat a title.

(A) someone in an armchair will have written the manual in English, translating it from the original Japanese produced by (B). However;

(Z) The actual point that I was seeking to make was that many professionals, quasi professionals and trades fall into the trap of thinking that their experience is a substitute for RTFM. Often it is not. Always done it that way does not mean that they have always done it right.

Let me give you an example. Since you like @30 years this is from about 30 years ago and a plumber of >30 years experience. A good plumber BTW. Now, at that time general experience was that most English showers were lousy. He said he was going to tee off the nearest feed. I RTFM which clearly said that the feed had to go right back to the hot water tank. We had a debate, he followed the shower manual and, no prizes for this,a decent shower in England. Gravity feed before the days of shower pumps.

Mind you, the reverse can also apply. A friend of mine who was an engineer in the RAF recounted how for a minor fault the whole engine in a jet fighter had to be removed because the experts who designed the thing overlooked access. Hands on experience also has a valuable place.