ZF SD-10 Saildrive Oil Change out

[Nic35]

I am getting ready to change the oil in my ZF SD-10 saildrive and have a few questions. I see multiple recommendations for the transmission lubricant. Recommendations from old ZF manual is 3L-SAE 15W-40. I have seen references for ATF too. The boat yard was going to use gear oil.
A more recent ZF recommendation list-"The list of lubricants TE-ML 04, edition 01.04.2023 replaces all previous editions."[/I]
Engine oil according to the specification / requirement:
- API CD/CE/CF-4/CF/CG-4/CH-4/CI-4/CI-4 Plus/CJ-4/CK-4
and / or API SF/SG/SH/SJ/SL/SM/SN
and / or ACEA categories A/B/E
- Viscosity grade: SAE 15W-40
- Base oil API Group 1 / 2 / 3 / 4
Looks like a diesel engine oil, I havent heard of engine oil used for transmissions but that looks like what is being called for.

Manual says to use low pressure pump to fill oil from the drain hole at the bottom of the saildrive leg. Is it acceptable to add transmission oil to dipstick opening? Please let me know what you have done with your saildrives.
thanks
Rick

[ggray]

I just pour the oil (my SD20s use gear oil) into the fill/dipstick hole.

It might be days or weeks after I fill up before I run the engines so I don't worry that oil has made its way down and left no air pockets. That's the only thing I can think of that would benefit from "bottom filling".