Per operators manual,
TRANSMISSION OIL LEVEL
Check dipstick under seat, when oil is warm, to make certain transmission, differential and hydraulic system are properly filled with type "F" Automatic Transmission Fluid. For heavy duty or high tempera¬ ture service, straight 20W or 30W motor oil with API classification SE, CC or CD is recommended.
Manual, https://archive.org/details/manualsbase-id-202104/page/7/mode/2up
