This manual covers the Mitsubishi S6S-Y3T61HF/S6S-Y3T62HF Diesel Engines. These robust, water-cooled, 6-cylinder engines feature a 5.2-liter displacement and direct injection fuel system, delivering power outputs typically ranging from 80 to 100 horsepower. Engineered for reliability and durability, these engines are designed for a variety of applications where dependable performance is paramount. Their construction emphasizes efficiency and longevity, making them a solid choice for demanding operational environments. The purpose of this English-language service repair manual is to provide comprehensive guidance for the maintenance, repair, and technical understanding of the Mitsubishi S6S-Y3T61HF/S6S-Y3T62HF Diesel Engines. It includes detailed information on lubrication, recommended oil types, capacities, and service intervals for oil and filter changes, which vary based on application and usage hours. This resource is essential for owners, mechanics, and technicians to ensure optimal engine performance, longevity, and adherence to emission standards through proper upkeep and troubleshooting.