This technical manual covers the John Deere 4555, 4755, 4955, 4560, 4760, and 4960 series tractors, produced primarily in the late 1980s and early 1990s. These heavy-duty agricultural machines are renowned for their robust engineering, high horsepower output, and durability, designed for demanding large-scale farming operations. Key features include advanced cabs for operator comfort, powerful John Deere 6000 series turbocharged diesel engines, and versatile transmission options such as Sync-Shift and Powershift, all contributing to their reputation for reliability and performance in challenging fieldwork. This comprehensive service manual provides detailed information essential for the maintenance, repair, and servicing of these John Deere tractors. It covers a wide array of systems, including engine overhaul, cooling, fuel, lubrication, powertrain, hydraulics, steering, braking, and electrical systems. The manual includes routine maintenance procedures, fluid specifications and capacities, component disassembly and reassembly instructions, troubleshooting guides, and complete electrical schematics. Its purpose is to equip owners, technicians, and mechanics with the necessary knowledge to ensure optimal performance, longevity, and operational efficiency of the tractor.