TRUCK SERVICE MANUAL
In examining the drive line, it would be well to start with a review of drive shaft operation. A critical examination
of why it is there and what it must do may be helpful in analyzing its effect on the entire drive line system. A driveshaft's
functions can be briefly described as follows:
It must transmit torque from the transmission to the axle. This requirement makes it necessary that the
driveshaft be capable of transmitting the maximum low gear torque developed by the engine and
transmission ratio and any shock loads which may develop. It must also be capable of rotating at the
maximum speed required for vehicle operation. This speed is often engine speed increased by an
overdrive ratio in the transmission.
The driveshaft must operate through constantly changing relative angles between transmission driveshaft
3. The length of the driveshaft must be capable of changing while transmitting torque. Length changes are
caused by necessary axle movement due to torque reaction, road deflections, braking loads, etc.
CTS-2730 Page 4
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