This manual covers Ford New Holland 230A, 231, 335, 340, 340B, 420, 445, 455A, 531, 532, 535, 540A, 540B, and 545A tractors produced between 1975 and 1983. These robust utility tractors, descendants of Ford's renowned agricultural line, are known for their reliability and versatility in farming and general-purpose applications. Featuring diesel engines typically ranging from 40 to 70 PTO horsepower, they are equipped with durable cast-iron construction and straightforward mechanical controls, designed as efficient workhorses for demanding tasks. This comprehensive factory service repair workshop manual provides detailed guidance for all service and repair needs. It covers every aspect of maintenance, troubleshooting, and repair, including in-depth procedures for the engine, transmission, hydraulics, electrical systems, chassis, and operator station. With hundreds of pages of detailed information, including photos and exploded diagrams, this manual is an essential resource for owners, mechanics, and technicians seeking to perform accurate and efficient servicing, from routine maintenance to complete overhauls.