This Field Assembly Manual provides comprehensive guidance for the Komatsu WA800-3LC Wheel Loader, serial numbers A50001 and up. Engineered for demanding industrial and construction applications, this robust machine features a powerful Komatsu SAA6D170E-3 engine delivering up to 363 kW (487 HP) and an advanced Hydro-Shift Transmission for efficient operation. Its substantial operating weight of 74,500 kg and a rated load capacity of 22,000 kg underscore its heavy-duty capabilities. The WA800-3LC is designed with reliability and performance at its core, ensuring productivity in challenging environments. This manual serves as an essential resource for understanding the assembly, adjustment, and maintenance of the Komatsu WA800-3LC. It details the step-by-step assembly procedures, parts installation, and post-assembly adjustments, supported by clear diagrams, schemes, and actual photo illustrations. Furthermore, it covers critical maintenance procedures, including refill capacities for engine oil, hydraulic tank, transmission oil, and radiator coolant. This English-language manual is designed to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of their WA800-3LC wheel loader.