This manual covers the Komatsu WA120-1LC Wheel Loader, a robust piece of equipment designed for demanding operational environments. Engineered for reliability and efficiency, this model features a powerful Komatsu S4D102E-1 diesel engine, a versatile Powershift transmission with four forward and four reverse gears, and a substantial operating weight of 9800 kg. Its dimensions, including a length of 6505 mm with the bucket on the ground and a width over tires of 2460 mm, are optimized for maneuverability and performance in various applications. The WA120-1LC is built to deliver consistent productivity and durability. The purpose of this comprehensive Workshop Service Repair Manual is to provide detailed guidance for the maintenance, repair, and servicing of the Komatsu WA120-1LC Wheel Loader. It includes essential technical specifications, detailed procedures for engine and transmission maintenance, information on fluid capacities, and guidelines for chassis components. Owners, technicians, and mechanics will find the information necessary to ensure the optimal performance, longevity, and safety of the equipment. This manual serves as an indispensable resource for all aspects of vehicle upkeep.