Transmission Arrangement and Method for Agricultural Vehicle

A tractor transmission including a range gearbox having an input shaft driven from a prime mover through a main clutch, an output shaft, an auxiliary drive shaft driven from the prime mover independently of the input shaft, and a torque fill drive system operative between the auxiliary drive shaft and the range gearbox output shaft including a torque fill clutch operative to transmit torque from the auxiliary drive shaft to the output shaft of the range gearbox when the torque fill clutch is engaged, so that when drive to the input shaft is interrupted to change gear, the torque fill clutch is engaged to transfer drive from the auxiliary drive shaft to the output shaft and maintain momentum of the vehicle. The system may transmit torque to the output shaft through a lay shaft of the range gearbox or through a ground speed PTO drive.