So as I've read numerous prior posts, I just want to confirm as I get ready to 'stock' fluids I need. The GL4, like Sta-lube, is NOT synthetic and we do NOT want to use synthetic in these old units, especially if we are just topping off fluids. The GL4 is used for the differentials, the tranny, the transfer case and the PTO and the Ross steering box. The corn grease is used in the knuckles only. Oil is up for debate on convention vs synthetic. Since I have both a CJ5 and a Willys wagon, I'm thinking just get enough to have on hand. When inspecting both differentials, I might as well change fluids and gaskets so how much should I expect to use on those initially?