Bushing — Link Counterbore Wear
CAUSES: Rotational sliding contact with
link counterbore and abrasives (always a
result of internal wear pitch extension).
ACCELERATORS: Horsepower, weight
and speed of machine; abrasiveness, loss
of sealing effect and snakiness, impact,
terrain packing loads, and maneuvering.
Track tension, too wide shoes, worn rear
rollers and high speed non-productive
work are main controllable variables.
EFFECTS: Reduces re-sealability of joint.
Reduces internal wear life and link rebuild-
ability after turn.
REMEDIES: Same as “Internal Pin and
Bushing Wear.”
Structural Problems on Sealed
Track Bushings
The destruction limitation of a Sealed Track
joint is usually due to structural failure in the
bushing caused by cracking or loosening
after internal and/or external wear limits are
exceeded. The most common causes, accel-
erators effects and remedies are shown here.
Also see “Sealed and Lubricated Track
Bushing Structural Problems.”
Bushing Cracks
(Through the entire wall)
CAUSES: Exceeding internal wear limit
and/or exceeding external wear limit for
respective degree of impact. (Crack can be
in several positions and configurations).
ACCELERATORS: Any loads between
sprocket and bushing caused by horse-
power, weight, speed, impact and terrain,
too-wide shoes, worn rear rollers, too tight
track and exceeding internal wear limits
are primary controllable variables.
EFFECTS: Depending on degree of cracking
and/or loss of bushing wall material, bushing
may not have strength to provide wear life
potential of back side after turn.
REMEDIES: Eliminate or reduce control-
lable accelerator variables.
Bushing End Cracks
CAUSES: Impact contact with counterbore
following internal wear and snakiness.
ACCELERATORS: Same as “Bushing End
Wear” and “Bushing Counterbore Wear.”
REMEDIES: Do not exceed internal wear
service limits.
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General Information
SEALED TRACK PINS & BUSHINGS