Figure 12-23.Patterns of tire wear.
2. Shimmy at low speeds:
a. Low or uneven tire pressure
b. Loose linkage
c. Worn ball joints
d. Caster incorrect or uneven
3. Vehicle wanders:
a. Tire pressure incorrect
b. Caster or toe incorrect
c. Suspension components
4. Steering wheel not centered:
Toe-in out of adjustment
Steering components bent
Steering wheel not properly placed on
5. Steers hard:
a. Low tire pressure
b. Binding steering assembly or misadjusted
c. Excessive caster
d. Steering and suspension units not properly
6. Tire wear (fig. 12-23):
Underinflation causes wear at tread sides
Overinflation causes wear at tread center
Excessive camber causes wear at one tread
Excessive toe-in or toe-out on turns causes
tread to featheredge
A misaligned front idler or track frame will cause
many hours of project lost time and could cost several
hundred dollars to replace worn-out components. You
must know what components will be affected and what
is involved in the proper alignment process. So, when
this condition does arise, you will be able to diagnose it
properly and take the corrective action needed to keep
your equipment in the field and on the job.
Track frame misalignment can allow tee-out. This
could cause excessive end wear of track pins, rail side
wear and sprocket tooth gouging of the inside of the
links, side wear of the sprocket and sprocket teeth,
off-center external wear of the bushings, and flange
wear of rear rollers. Misalignment of the front idler can
cause wear of the front idler flange, the front track roller
flanges, and the link side rails.
The use of track guiding guards keeps the track in
proper alignment. These are called wear bars and plates.
They are shimmied to align the idler with the track
rollers. The side wear plates guide the idler, as it recoils
back and forth. These guards should be reconditioned or
adjusted to proper thickness, so they will guide the track
squarely into alignment with the track rollers.
The front guiding guards receive the track from the
idler and hold it in line for the first roller. The front roller
then can be used fully for its intended purpose-that of
carrying its share of the tractor load without having to
climb the sides of the improperly aligned track.
The rear guiding guards hold the track in correct
alignment with the driving sprocket, permitting a
smooth, even flow of power from the sprocket to the
track. With proper alignment, the gouging of link sides
and sprocket teeth is eliminated.