The Fendt Farmer 400 Vario Series, encompassing models 409 Vario, 410 Vario, 411 Vario, and 412 Vario, represents a significant advancement in agricultural machinery. Introduced in the early 2000s, this series is renowned for its integration of the groundbreaking Fendt Vario continuously variable transmission (CVT) system, a key technological innovation that offers unparalleled operational flexibility and efficiency. These tractors, built with Fendt's characteristic German engineering, are designed for demanding agricultural applications, delivering robust performance, reliability, and operator comfort. Their powerful Deutz engines, providing a horsepower range from approximately 85 to 120 HP, are engineered for strong low-end torque, making them ideal for a wide array of tasks. This comprehensive workshop service repair manual provides in-depth technical information essential for the maintenance and repair of your Fendt Farmer 400 Vario Series tractor. It covers all critical systems, including the engine, Vario transmission, hydraulics, electrical system, chassis, braking, and steering. Detailed procedures for routine maintenance, component disassembly and assembly, troubleshooting, and diagnostics are included, offering insights previously available only to professional dealers and technicians. The manual's extensive coverage, presented in a clear and organized format, empowers owners and mechanics to ensure the longevity, optimal performance, and cost-effective upkeep of this valuable agricultural investment.