Figure 13-15.-Single-speed, single-gear, power takeoff.
of mesh with the countershaft gear. The spring-
loaded ball holds the shifter shaft in position.
On some vehicles you will find power take-off
units with gear arrangements that will give two
speeds forward and one in reverse. Several forward
speeds and a reverse gear arrangement are usually
provided in power take-off units that operate winches
and hoists. Their operation is about the same as that
in the single-speed units.
PROPELLER SHAFT ASSEMBLIES
The propeller shaft assembly consists of a
propeller shaft, a slip joint, and one or more universal
joints. This assembly provides a flexible connection
through which power is transmitted from the
transmission to the live axle.
The propeller shaft may be solid or tubular. A
solid shaft is stronger than a hollow or tubular shaft
of the same diameter, but a hollow shaft is stronger
than a solid shaft of the same weight. Solid shafts are
used inside a shaft housing that encloses the entire
propeller shaft assembly. These are called torque tube
drives.
A slip joint is put at one end of the propeller
shaft to take care of end play. The driving axle,
attached to the springs, is free to move up and down,
while the transmission is attached to the frame and
cannot move. Any
13-13