1. Orientation: A FWD transmission is mounted *transversely* (across) the vehicle, while a RWD transmission is typically mounted *longitudinally* (along the length) of the vehicle. This fundamental difference dictates the entire design and packaging of the transmission and its surrounding components.
2. Drive Shaft Arrangement: FWD transmissions incorporate a drive shaft that angles sharply towards the front wheels, usually with CV (constant velocity) joints to accommodate the changing angle during suspension travel. RWD transmissions typically use a driveshaft that runs along the length of the vehicle to a differential at the rear axle, with simpler, less complex joints.
