This manual covers the John Deere 4055, 4255, and 4455 series tractors, produced primarily in the late 1980s and early 1990s. These robust machines are known for their powerful John Deere 400 Series diesel engines, ranging from approximately 5.9 to 7.6 liters, and are equipped with John Deere's reliable PowerShift transmission for efficient operation. Engineered for demanding agricultural applications, these tractors represent John Deere's commitment to durability, performance, and operator productivity, building upon a strong legacy of agricultural machinery manufacturing. The purpose of this comprehensive service repair technical manual, TM1458, is to provide detailed information for the maintenance, diagnosis, and repair of the John Deere 4055, 4255, and 4455 tractors. It covers all major systems, including the engine, transmission, hydraulics, drivetrain, and electrical systems, offering step-by-step procedures, troubleshooting guides, and technical specifications. This manual is an essential resource for professional mechanics, farm owners, and technicians seeking to ensure the optimal performance and longevity of their equipment.