Re: 15r74s gearcase oil
You have a drain/fill screw on the bottom and a vent screw above it. Both are slotted screws, do not remove the phillips screw between them. Pull the drain and vent screws get a pump style gear case filler, screw it into drain/fill hole (bottom) and start pumping. When oil comes out the top hole, put the top plug in remove filler and put the bottom plug in. You should use new nylon washers behind the plugs. I think that's about it. Oh one quart will do the job two or three times. 300ml is what I remember. Best of luck. Rick.
