Swapping Carrier Rollers
Carrier rollers can be swapped from front
to rear and left to right to help balance
their wear life in cases where conditions
have caused unequal wear rates. Criteria
are: greater than 1.5:1 ratio and average
less than 60 percent worn.
Carrier Roller Wear Patterns
There are three principle wear patterns
found on carrier rollers. In each case the
effect on the links may be more critical,
considering total undercarriage life, than
on the carrier rollers themselves.
Tread Wear
(Uniform)
CAUSES: (1) Rolling and sliding motion
with link rail (top) surfaces. (2) Sliding
contact with packing material on roller
frame.
ACCELERATORS: Machine speed.
Weight of track which is governed by shoe
width including packing material. Track
tension is primary controllable variable as
tight track increases loads and too loose
track causes impact between links and
tread surface, particularly in forward
motion.
EFFECT: Wear life of carrier roller and
links. No other components affected
unless service limit exceeded, then flanges
may strike bushings causing unusual wear
pattern and premature failure.
REMEDIES: Maintain proper track tension
and reduce or eliminate other controllable
accelerator variables. Rebuild or replace
carrier roller shell when service limit reached.
Uneven Flange Side Wear and Off-
center Tread Wear
CAUSES: Rolling and sliding contact
with link rail top and sides not aligned
with carrier roller.
ACCELERATORS: Same as “Carrier
Roller Tread Wear” plus terrain and side-
hill; and misalignment of carrier rollers,
sprocket and/or idler. Offset shoes will
move track to outboard side.
EFFECTS: Loss of potential wear life and
rebuildability of carrier roller and links.
REMEDIES: Reduce or eliminate control-
lable accelerators. Swap carrier roller to
balance wear.
Flat Spots on Tread
CAUSES: Sliding contact with link rail
tops when carrier roller not turning.
ACCELERATORS: Same as “Even Tread
Wear.” Packing between roller frame and
carrier roller is principle cause of seizing.
EFFECT: Reduced wear life and rebuild-
ability of carrier rollers. Accelerated wear
on links.
REMEDIES: Clean packing material away
from carrier rollers.