Flange Top Wear
CAUSES: Rolling and sliding contact
with link pin bosses after loss of clearance.
ACCELERATORS: Same as “Tread Wear.”
EFFECTS: Reduces roller rebuildability.
Damages link pin bosses with resulting
pin retention and rebuildability loss.
REMEDIES: Same as “Roller Tread Wear.”
Roller Welding, Swapping,
or Replacement Guidelines
Weldability
The main criteria determining roller tread
rebuildability is outer and/or inner flange
condition. Since no wear chart type infor-
mation is possible and measurements are
difficult, the condition of the flange must be
described in subjective, comparative terms.
Rollers can be welded if the maximum
tread wear is between 70-110 percent, but
100 percent represents the optimum.
The Undercarriage Reconditioning Cost
Analysis computer program (SEBD0700) is
available to analyze the costs and profitabil-
ity of welding undercarriage components.
Roller Swapping
Due to the expected unbalanced wear rate
between rear, front and center rollers
under many conditions, it’s often desirable
to swap rollers to and from front and/or
rear positions to center position midway
through their average wear lives. One con-
venient time for this is when pin and
bushing or shoe maintenance work is
being done. The result will be to have all
rollers reach service limits at about the
same time.
The cost of roller swapping must be
compared with this end benefit. The
practice should be considered when the
percent worn of the most worn rollers
exceeds the percent worn of the least worn
rollers by a factor of 1.3.
Example of situation where roller swapping
at bushing turn time should be considered:
LINKS: 40 percent worn
BUSHINGS: 80 percent worn
ROLLERS:
ORIGINAL MOVE TO
POSITION % WORN TYPE POSITION
NUMBER
Front (1) 50% D.F. 4
2 40% D.F. No change
3 30% S.F. Rear (7)
4 30% D.F. Front (1)
5 40% S.F. No Change
6 40% D.F. No Change
Rear (7) 50% S.F. 3
Average % Worn 40% (Equal Links 40% Worn)
Most worn roller exceeds least worn roller
percent worn by over 1.3 (50% = 1.66)
30%
If not swapped, front and rear rollers will
be critical when link is only 80 percent
worn and will cause pin boss to roller
flange interference when link is 90 percent
worn.
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TRACK ROLLERS
General Information