I'm not sure on a 3000, but my Ford is close to the same thing, and the filter on mine is under the platform where your left foot goes when you're driving the tractor. Also, if the 3PH is dropping , you might check the hydraulic oil level in the final drive. There's a squareheaded plug in front of the rear axel, near your right heel, about the height of the middle of the axel, take the plug out and fill with oil till oil runs out this hole. Oil goes in a filler plug on top of the rear axel, under the seat. Replace plug and go.