What type of hydraulic oil should I put in my John Deere 4455 transmission?

For your JOHN DEERe 4455 transmission, you should use John Deere Hy-Gard hydraulic oil or an equivalent oil that meets the JDM J20C specification. This oil is designed to provide optimal performance and protection for the hydraulic system and transmission components. Always check the owner's manual for specific recommendations and ensure the oil is clean and free from contaminants.