ATF or Engine Oil in the Gearbox

[lordgeoff]

I have a Perkins M90 attached to a gearbox of unknown brand. The yacht is an ex Moorings 505. (Beneteau 50)
The gearbox is likely a
Newage PRM 500D or
ZF-Hurth HBW 450A
but not sure as I cant see a model
On the oil filler the gearbox has a sticker "ATF".
When I bought the yacht the advice was to put a light engine oil in the gear box which was done.
It looked like engine oil in the gearbox when I first drained it after buying the yacht.
I change the oil in the gearbox regularly at about 400 hours.
It works fine and I have done a bit over 2,000 hours in the last 18 months.
There is lots of stuff on the net about Engine oil Vs ATF.
What is the definitive advice?
Cheers.
Pauline



THERE IS NO NEED TO BARK IF YOU HAVE A DOG

[model 10]

No such thing as a definite answer around here. Given that it's a transmission and it says to use ATF... We have an old transmission (Paragon) and it says to use ATF also. However it will slip like crazy if you do, so we use 30wt.