1. Length and Angle: FWD driveshafts are generally much shorter because the transmission and differential are located near the front wheels. They may also operate at a shallower angle compared to RWD driveshafts which often need to transmit power over a longer distance and at a steeper angle to accommodate the engine's position at the front.
2. Constant Velocity (CV) Joints: FWD driveshafts almost always utilize constant velocity (CV) joints at both ends. This is crucial because the driveshaft's angle changes constantly as the wheels steer and articulate during suspension travel. RWD driveshafts, on the other hand, typically only require CV joints at one end (the transmission end) or may even use universal joints (U-joints) at both ends, especially in simpler designs. While some modern RWD vehicles do incorporate CV joints, their design considerations differ from those in FWD applications due to the differing operating angles and stress levels.
3. Shaft Material and Design: While both FWD and RWD driveshafts need to be strong, FWD shafts often experience different stress profiles. Because of the constant change in angle and the use of CV joints, FWD shafts may be designed with more emphasis on torsional flexibility and resistance to bending under varying angles. RWD driveshafts might prioritize straightforward strength and stiffness, particularly in heavier vehicles. The specific material selection and overall design (tubular vs. solid, etc.) may reflect these differing priorities.
