Lincoln F6TZ-7A039-F Transmission Extension Housing

Operationally, all transfer cases mentioned perform the same function. In 2WD mode, power is transferred from the transmission to the Input shaft of the transfer case, which then drives the output shaft through a non-functional planetary gear set. Shifting into 4WD mode locks a previously free wheeling gear onto the 2WD output shaft, connecting a second output shaft for the front driveshaft via a multi-row chain. This completes the transfer of power to the front wheels. Shifting into 4WD low activates the transfer case planetary gears for gear reduction of the 2WD output shaft, providing reduced gearing to both axles. The transfer cases differ in the mechanical means used for planetary gear reduction and shift mode mechanisms. Additionally, all transfer cases have an oil pump driven by the rear output shaft to maintain pressure during normal operation and towing.