This workshop manual provides in-depth technical guidance for the maintenance, troubleshooting, and repair of the John Deere 4045 and 6068 PowerTech diesel engines. It covers comprehensive procedures for disassembly, inspection, reassembly, and adjustments of key components, including the fuel system, cooling system, lubrication system, and electrical system. The manual includes detailed diagrams, technical specifications, and step-by-step instructions to assist technicians in performing accurate repairs. Additionally, it features routine maintenance schedules and diagnostic information to ensure the engines operate efficiently and reliably. This manual is an essential resource for professionals responsible for servicing John Deere 4045 and 6068 PowerTech engines.