Yanmar 2GM20 KM2P Transmission Oil level question

Yanmar 2GM20 KM2P Transmission Dipstick Location
Yanmar Owner
Yanmar Owner

Transmission Oil level question – please can someone help?

I have a Yanmar 2GM20 from the early 90’s, with (I believe, according to the manual) KM2P transmission. Please can someone help me understand where the “full” line is on the dipstick, that the manual is telling me to top it up to? There’s nothing obvious to show “max” and “min” like there is on a car; all there is, is a single line near the bottom of the dipstick, pretty much where the black arrow is on the attached photo from the manual.

The reasons I’m not jumping to conclusions that this lowest line is the “full” line are that;
In the manual, figure 39 as pictured is NOT specifically referring to the level line – it’s simply showing where the dipstick is FOUND, so the location of the arrow could be total coincidence
The line is only about 4-5mm from the bottom – that seems like a very low location for a “full” line
Finally, when I checked it after it’s most recent service, IIRC the oil pretty much came all the way up to the top of the dipstick – but of course there’s no combustion in that chamber so the oil’s completely clear, and I can’t be 100% sure. I’m now questioning my original memory (and my sanity!)
What I CAN be 100% sure of, is that I don’t want to go out next weekend and kill my transmission mid-trip, by just guessing!!!

The group were agreed – the line indicates the required fill level. Additionally, the oil is to be measured with the cover/stick resting loose on the opening. Concern from some that the mark, being so close to the bottom of the dipstick, signified very little oil was dismissed – “gears don’t use oil. Only a full mark is provided.” It’s a surprisingly small amount of oil, but correct. Do not put more oil “just to be safe’ … It can cause damage to the transmision.