This manual covers SL-Series diesel engines, including models S3L, S3L2, S4L, S4L2, S3L-T, S3L2-T, S4L-T, and S4L2-T. These engines are known for their robust engineering and reliability, offering power outputs ranging from approximately 20 to 40 HP depending on the specific configuration and turbocharging. The SL-Series engines are designed for dependable performance across a variety of demanding applications, reflecting a commitment to quality and durability in engine manufacturing. This Factory Service Repair Workshop Manual in English provides comprehensive guidance for the maintenance and repair of these engines. It includes detailed information on engine oil specifications, valve clearance adjustment, fuel injection timing, fuel filter service, fuel system priming, idle RPM settings, and fan belt service. Furthermore, the manual offers essential service data, tightening torques, sealant information, and lists of special tools, all supported by clear illustrations, diagrams, and charts to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of their SL-Series engines.