Fill plug is directly behind the seat. A plastic cap about 2 1/2 inches across. Screw it out and fill to correct mark on dipstick. Dipstick should be by your right heel as you sit in the seat. Depending on your serial number, could be a metal screw in dipstick, or a red plastic handle the pulls straight up. Same fill plug and dipstick for hydraulic and transmission. All the same oil.