Undercarriage Inspection Tips
Field Fact: 50% of the cost of owning and operating a machine are related to its undercarriage
C.N. Wood has developed guidelines to help you get the most out of your undercarriage with the lowest cost possible. To help control costs, schedule regular maintenance inspections with C.N. Wood's certified technicians. We will monitor wear with our ultrasonic measurement tool, which provides reliable estimates of remaining hours of life.
Early detection of wear, misalignment and damage is key in avoiding serious, costly repairs.
Sprockets
Carefully monitor sprocket wear, which is a sign of operating problems and can
indicate the condition of the internal pin and bushing assembly. Sprocket replacement
is usually necessary whenever the mating surface of the bushing is changed, when
rotating or replacing bushings or replacing the chain assembly.
Bushings
Keep track of undercarriage wear by looking for bushing wear and premature link pitch
elongation. Look for differences in component wear patterns (e.g., left versus right or
front versus rear), which can indicate hidden problems like misalignment or poor
operator habits.
Bushing Turn
Turning the bushing 180° to use the unworn area allows using not only the entire
wear surface of the bushing but also more of the link. Timing is key, however. If the
bushing has worn past the wear life limit, the chances of damage to the bushing
increases during the processing of pressing in and out, because the thickness of the
bushing wall may be dangerously thin.
Components
Watch for component damage, such as cracks, bends and breaks, which can lead to
interference and malfunction.
Alignment
Misalignment causes unnecessary wear to all undercarriage components. The most
common type is idler shift, which can be fixed by adjusting idler shims. The quickest
way to detect an alignment problem is to look for anything shiny that should not
normally be shiny. Indicators that the track frame alignment system needs adjusting
are: inside of track links are scuffed and shiny, roller and front idler flanges show
wear, and sides of sprockets are coming in contact with the inside of track links.
Rollers
As the track roller tread area wears, the roller flanges grow closer to the link pin boss
area. The pin boss area will be damaged if the flanges are allowed to come into
contact with the pin boss. Damage in the pin boss area can eliminate the bushing
turn option. Roller flanges contacting this area will wear away structural material and
the pin end will be damaged. Cracking can occur when pressing the pin out or in, if
the structure is weak. During the pressing process, damage and “flaring” to the pin
end can cause damage to the internal pin boss area, and the pin boss cannot
properly retain the pin after reassembly.
Repositioning rollers from higher wear positions, at both the front and rear of the machine, to less wear center positions can be helpful to alleviate wear. Check rollers for oil leakage, which would mean oil loss, resulting in possible component seizing, which causes quick, excessive wear and damage.
Nuts and Bolts
Check for loose nuts and bolts, which will interfere with moving parts and cause
abnormal wear, bolt hole wallowing, bolt breakage, accelerated misalignment and
component loss. If bolts are not tight enough, vibration will slowly loosen them. If
they are too tight, they will fail prematurely because their structural integrity is
weakened.
