The YANMAR TNM Series, specifically the 3TNM68 and 3TNM72 models, represents a line of industrial engines engineered for demanding applications. These engines are built with a focus on reliability and robust performance, making them suitable for a wide range of industrial uses where dependable power is essential. Their design prioritizes durability and efficiency, reflecting YANMAR's commitment to providing high-quality engine solutions for professional environments. This Workshop Service Manual provides comprehensive guidance for the maintenance, repair, and servicing of the YANMAR TNM Series engines. It covers critical areas including general service information, periodic maintenance schedules, and detailed procedures for the engine, fuel system, cooling system, lubrication system, starter motor, alternator, and electrical wiring. The manual is designed to assist owners, technicians, and mechanics in understanding and performing necessary tasks to ensure optimal engine operation and longevity, featuring clear writing, pictures, diagrams, and illustrations.