The two brakes that provide control of the winch
drum are as follows:
The WORM BRAKE SHAFT prevents the
NEVER install a shear pin that in not of the
winch drum from rotating under load when the
proper shearing strength. Damage to the winch
power takeoff is disengaged.
will occur when overloaded.
The SHIFTER BRACKET BRAKE prevents
the drum from overrunning the cable when the
cable is being unreeled.
Some winches may be equipped with an automatic
level-winding device to spool the cable on the drum in
tight, even coils, and layers. This prevents crushing of
the cable due to loose, crossed coils and layers, and it
allows off leads of the cable while maintaining level
A broken shear pin usually causes faulty operation
of winches. Internal damage of the winch can be
caused by the use of a shear pin that has too high a
breaking strength. Internal winch failure, resulting
from overload, is commonly found to be sheared keys
or a broken worm shaft. Often, when the cable is
wound unevenly under tension, the winch housing will
be cracked or broken. This will require replacement of
The winch that you will most likely encounter
on construction equipment is the one attached to
the rear of a crawler tractor, also known as a dozer.
It is mounted on the rear of the dozer (fig. 6-32) and
is directly geared to the rear power takeoff. This
arrangement permits development of a line of pull
that is 50 to 100 percent greater than straight dozer
pull. The winch is used for uprooting trees and
stumps, hoisting and skidding stress, freeing mired
equipment, and support amphibious construction
When performing maintenance on a winch, ensure
that the gear case has the recommended amount and
type of lubricant. Should disassemble of the winch be
required for repairs, follow the procedures given in the
Figure 6-32.Winch attachment on a dozer.