This workshop service repair manual covers YANMAR 3TNV and 4TNV series diesel engines, designed for installation in Hyundai mini excavators (5TON, -7 Series) and skid steer loaders. These engines are engineered for robust performance and reliability in demanding operational environments. The manual details critical components and systems, including the turbocharger, lubrication system, cooling system, fuel injection pump/governor, starting motor, alternator, and electric wiring, ensuring comprehensive support for these essential power units. This comprehensive English-language manual provides detailed guidance on routine and preventive maintenance, as well as in-depth repair procedures for engine disassembly, inspection, and reassembly. It includes essential information on troubleshooting, inspection and adjustment, service standards, and tightening torques for bolts and nuts. This resource is invaluable for owners, mechanics, and technicians seeking to maintain the optimal performance and longevity of their YANMAR engines.