Figure 36-5. Typical Positions of Transfer and Power takeoff Control Levers for Two-Speed Transfer
Assembly with Power Takeoff.
Section II. WINCHES
36-7. Purpose. Using its winch and some type of
36-9. Operation. The typical front-mounted winch is a
rigging, a vehicle can pull itself or another vehicle
Jaw-clutch worm-gear type. The winch consists of a
through such obstacles as very muddy or very rough
worm and shaft which drives a worm gear that is keyed
terrains. This is the primary reason for providing
to a shaft (fig. 36-6). A bushed drum is mounted on the
winches on standard military vehicles. The winch in this
worm-gear shaft which is controlled by a sliding clutch.
case is powered by the engine of the vehicle through a
The wormshaft is driven by a drive shaft connected to a
power takeoff from the transmission. Field expedients
power takeoff unit mounted on the transmission. The
may utilize the winch for such devices as simple cranes
hand-operated sliding clutch is keyed to the worm-gear
in a field shop. However, on special equipment and
shaft outside of the winch drum, and must be engaged
vehicles, winches are furnished for special purposes
with the jaws on the side of the winch drum when the
such as powering the crane of a wrecker. Some of these
winch is to be operated. Disengagement of the sliding
latter winches are powered by separate gasoline
clutch permits the drum to turn on the worm-gear shaft.
Two brakes are provided to control the winch drum. The
wormshaft brake prevents the winch drum from rotating
under load, when the power takeoff is disengaged. The
36-8. Mounting. Generally, the winch is mounted
shifter bracket brake prevents the drum overrunning the
behind the front bumper and is secured to the front
cable when the cable is being unreeled. A shearpin on
crossmember of the frame or between the two side
the worm drive shaft prevents damage from overloading.
frame rails. It may be mounted behind the cab. The
The power takeoff is controlled by a shift lever located in
tandem winch assembly, for example, consists of a front
the driver's compartment.
(upper) and rear (lower) winch that is secured to a
mounting assembly fastened to the chassis frame at the
rear of the cab.