CAUSES: Sliding contact with corre-
sponding bushing position. With Sealed
and Lubricated Track it indicates moderate
degree of packing. With Sealed Track it
indicates combined degree of mismatch
resulting from internal wear plus packing.
ACCELERATORS: See “RDS and FDS
wear on Sealed and Lubricated Track and
Sealed Bushings.”
EFFECTS: Reduces potential wear life of
sprocket segment due to reduced strength
of tooth in driving position.
REMEDIES: Reduce or eliminate control-
lable accelerator variable listed under
“Sealed and Lubricated Track and Sealed
Bushing FDS and/or RDS Wear” Positions.
Change sprocket as indicated by sprocket
reuse gauge at bushing turn or replacement
time only. Action taken should be in con-
sideration of bushing, not sprocket segment
except in extreme cases when loss of tooth
could cause final drive damage.
Reverse Drive Side Tip Wear
(corresponding to more than 60° from
vertical on bushing wear).
CAUSES: (1) Severe packing effect in the
absence of track pitch extension from
Sealed and Lubricated Track or early hour
Sealed Track cause bushing to have interfer-
ence with sprocket tooth tip upon entry at
the bottom of the sprocket in forward
motion and/or interference with tooth tip
upon exit at the bottom of the sprocket in
reverse motion. (2) Too loose of track with
more than 1" (3/4" on one carrier roller
machines) of slack results in “back jam-
ming” the bushing at the bottom of the
sprocket in reverse motion.
NOTE: To determine the cause of reverse
drive side tip wear note the direction of
the scratches on the tooth tip. If they point
toward the tip then the cause is probably
too loose track; if they point toward the
root, the cause is probably severe packing.
See further discussion under “How to
Interpret Sealed and Lubricated Track
Bushing Wear Patterns — Forward
and/or Reverse Drive Side Wear Pockets.”
ACCELERATORS: (1) For Packing —
same as “Bushing FDS and/or RDS
Pockets” (2) For too loose track — same
as “Bushing FDS and/or RDS Pockets”
except track tension needs to be increased
by removing excess slack.
EFFECTS: (1) & (2) No adverse effect on
sprocket itself when in absence of other sig-
nificant FDS and/or RDS wear patterns.
Does not affect sprocket reusability or
ultimate wear life as vertical position should
take over as most worn on Sealed and
Lubricated Track and FDS/RDS wear
should take over as most worn positions with
Sealed Track following pitch extension.
REMEDIES: (1) If caused by packing —
reduce or eliminate controllable accelerator
variables, particularly too tight track. Do
not change segments based on tip wear
alone. Use sprocket reusage gauge to deter-
mine reusability following bushing turn or
replacement. Use mud/snow segments only
if packing material is constant and extrud-
able. (2) If caused by too-loose track —
adjust track to proper slack. Do not change
or replace segments based on tip wear
alone. Use sprocket reuse gauge to deter-
mine reusability following bushing turn or
replacement.
68
SPROCKETS
General Information