My grandson and I recently removed screen etc on my D type OD. After cleaning the screen and draining the old oil we just rigged up a long piece of plastic tubing to a funnel. Insert one end in fill hole while the funnel was up in the engine compartment. We measured the amount of oil suggested in the shop manual and slowly added it to the trans. When we had almost poured it all in we stopped and checked the level which was right at the bottom of the fill hole. So we drove it around a bit then came back and checked it again. No change. So it didn't quite take as much as the manual suggested, which I hate but full is full. I used 30 wt non detergent Amalie.