i've got the same engine/transmission. my borg warner manual specifically states dextron automatic
transmission fluid. there is no mention of
motor oil or hydraulic fluid.
you won't find this information in the perkins manual, (i have that too). the perkins manual is for the engine, not the transmission. it is in the borg warner manual that the po thankfully left on the
boat for me.
the engine of course uses
diesel grade motor oil. i've been using rotella t 15w-40 for seven years now and am perfectly happy with it. the perkins manual recommends chainging the oil and filter every 150 hours but i do mine every 100 hours. if you haven't run the engine for several months (being
on the hard, for instance) change the oil when you go back in regardless of the hours. i've been
buying my filters from napa which are actually made by wik - considered by many to be the best - and it only costs a few dollars more.
i also change my
racor fuel filters every 100 hours although the book recommends 300. don't know if that's really necessary but what the heck, it makes me feel better....