The final drive on a crawler tractor drives a complete track and undercarriage system on
each side of the equipment. Each link of the track is held together with a press-fit pin
and bushing to keep each link section in proper alignment with each other link section
during operation. This combination of parts is called a link assembly. Pressed together,
each section acts like a hinge, which
allows the chain flexibility when rotating on
the undercarriage. The track links also
provide a means for attaching the track
shoes that are bolted to the links. The
parts of each link assembly are induction
hardened to provide good wear
characteristics. Pins and bushings are
machined to provide a smooth bearing
between them, which also increases
durability. A master link or master pin
completes the track assembly.
The master link, as shown in
Figure 9-27
,
is slightly different from the rest of the
links. The bushing used in the master link
assembly is slightly shorter than the rest of
the bushings, and the master pin, as
shown in
Figure 9-28,
has a smaller
Figure 9-27 -
Master link.
diameter to facilitate easy installation and removal. Some manufacturer's master pins
can be identified by a mark or drill hole on the end of the outside face of the pin; yet
other manufacturers use a two-piece master link that bolts together. The master link
uses the same pins and bushings as the rest of the track, making splitting the track
easier because no special tools are required to disassemble the track. Before
attempting any maintenance or repairs to a track and undercarriage system, always
refer to the manufacturer's technical documentation or service manual.
Figure 9-28 -
Master pin.
NAVEDTRA 14050A
9-36