This workshop service repair manual covers the IVECO NEF 45, 60, and 67 Tier 3 Engine series, which are robust diesel engines designed for demanding applications. These engines feature 4-stroke, in-line configurations with supercharging and intercooling or aftercooling, and are available in 4-cylinder (4553 cc) and 6-cylinder (5880 cc, 6728 cc) variants. Equipped with Electronic Diesel Control (EDC), these engines are engineered for reliability and performance in various operational environments. This comprehensive manual provides detailed guidance for the repair, maintenance, and servicing of the IVECO NEF Tier 3 engines. It includes essential information on general maintenance planning, troubleshooting procedures, and specific maintenance steps for critical components such as the cylinder unit bushings, timing system, fuel system, lubrication system, cooling system, and injection feed system. Technical specifications, including tightening torques, are also provided to ensure accurate and effective service.