Anyone with a rider with the auto trans axle. Mine had started to get pretty weak and would hardly pull in my deep ditches and hills around shop and house. Did a bunch of reading and figured replace axle @ 800.00 on a 1500.00 mower or 3500. For new mower. Neither option appealed to me. Went to YouTube and found video on changing oil in it. Supposedly this could fix a lot of them. As usual they make it as hard as possible to accomplish this. Very few have a drain plug. Guy showed how to do this with a hand vacume pump which I happened to have and was lucky that fill plug was accasable by removing battery. Sucked out all the old oil I could get. Filled back with 5W50 pure synthetic, purged like manual said and now works like brand new. By the way these come with 20/50 motor oil so unlike hydraulic oil it will break down over time from the heat they operate under. Oil that came out was dark as if it had been running in a diesel. The syn will take a lot more heat. My unit has about 250 hr's on it. Take this for what it is worth to you and your mileage may vary.