As the power produced by the engine of a vehicle leaves the transmission, it still
must go through a series of complex processes before the vehicle begins to move.
The driveshaft is responsible for delivering the power from the transmission
to the axle, or the wheel itself. In the rear, it connects to the differential,
which takes the high rotational speed of the driveshaft, and slows it down before
delivering the power to the axles. As the vehicle is moving, the tires, the
axle and the differential will move up and down as the surface of the road changes.
The rear driveshaft usually uses a pair of universal joints to keep the
power to the wheels constant. With the universal joints, the driveshaft always
is at the correct angles to the transmission and the rear differential to deliver
the power consistently and without doing damage to any other parts. In the
front, the process is more complex.
The wheels not only react to the
movement of the suspension, but they also must be allowed to steer. In vehicles
with driven front wheels, the driveshaft uses constant velocity joints in the
place of universal joints. This type of joint is more flexible and can allow
for the lateral movement of the steering tires, especially when it is combined
with a slip joint. The constant velocity joint also produces less vibration than
the universal joint, making it much more suitable in the very short front driveshaft.
In any driveshaft, the joints will begin to suffer from the effects of
corrosion and foreign substances, often producing an audible grinding noise just
before the joints, and thus the driveshaft, need to be replaced. |
