“There’s no avoiding undercarriage wear on tracked machines,” said Jerry Pleasant, Case product support specialist crawlers. “But you can increase uptime, reduce owning and operating expense and extend the life of your undercarriage.”
Part of any good maintenance program starts before the sprockets are turning. Hopefully the contractor has inspected the job site, matched the size of the dozer to the job, viewed soil conditions and equipped the undercarriage for the job at hand.
Job-site conditions change, but certain questions should be answered — and the machine equipped accordingly — before it arrives at the job site. Among these questions are: Is a short or long track needed? Are standard or relieved (for extrudable material) sprockets needed? Does the job require a standard, wide track or low-ground-pressure gauge machine? Will this be low impact (dirt) or high impact (rock) loading on the components? Will this be more flat or hillside work? What shoe width is needed?
Once answers to these questions are addressed, Pleasant offers tips to help extend undercarriage life.
Whenever possible, match the track shoes to the underfoot conditions. Track shoes must provide adequate traction and flotation — the ability to stay on the surface of soft ground or mud — but should be no wider than necessary. Proper flotation occurs when the grouser fully penetrates the ground without letting the track shoes go below the surface. Wide shoes when not used in proper conditions place undue stress on rollers, idlers and the track chain, accelerating wear on the components.
Install rock guards before operating in rocky conditions. These really help keep rocks from getting stuck in the track. However, use of rock guards is not recommended when operating in mud or clay.
Avoid high-speed operation, particularly when reversing and in rough terrain. As travel speed increases, so do wear rates on all components. Reverse operation at high speed can be particularly damaging.
Avoid spinning the tracks. Spinning is non-productive and decreases undercarriage component life. Reducing track speed helps prevent slippage.
Avoid operating on concrete and other hard surfaces when possible. Operating on hard surfaces causes high-impact loads which increases undercarriage wear. If an application requires an operator to work on concrete, he should consider adding optional rubber pads to the tracks, or using rubber tracks. Rubber tracks not only reduce wear to the machine, they also can prevent damage to finished asphalt and concrete surfaces.
Vary operation and keep turns to a minimum. The type of work contractors typically do — such as continually working uphill, downhill, or sideways — increases wear on certain components. Frequent turning also adds stress and side wear to the components. If an operator must turn often, he should alternate turning directions so components wear more evenly.
Keep the tracks as clean as possible. When abrasive materials such as dirt and stones get packed in the tracks, they can really speed up the wear process. It’s especially important to clean the undercarriage more frequently in freezing temperatures. Consider parking the machine on planks or on a surface that will not freeze to the machine when the thermometer dips below freezing.
Check for loose or missing hardware on a regular basis. Be sure to replace all missing or damaged parts immediately. Also, tighten all bolts to specifications recommended in the service manual.
On lubricated track, visually inspect the machine each day for leaking rollers and track pins. The use of lubricated track has virtually eliminated internal pin and bushing wear. However, this track system is very dependent on seals. Left undetected, oil loss from a leaky seal will lead to a dried joint, which will increase pin and bushing wear.
Check and adjust the track tension on a regular basis, especially as job and soil conditions change. This is particularly important when operating in mud, sand or clay. These materials tend to pack in the track, so it may be necessary to loosen the adjustment to avoid operating with the tracks too tight. Incorrect track tension can accelerate wear twice as fast, rob horsepower and waste fuel.
As the undercarriage components wear, the operator can record the measurements. This will tell the operator the percent of material remaining and help make decisions on repair or rebuild options. It also can indicate if the wear is normal, or if there is a problem like misalignment or incorrect tension.
An equipment dealer can offer parts, service and application knowledge. Case dealers are trained to help customers select and obtain the different types of sprockets, guards and shoe widths needed. They also can help determine if sealed, sealed and lubricated or Case’s Extended Life Track (CELT) chain is right for the machine. CELT differs from other track in that it incorporates a bushing that is free to rotate on the standard track bushing. This distributes wear over the entire circumference of the bushing and, because the bushing is free to rotate, does not create scrubbing action between the sprocket and bushing as conventional track does. Case recommends CELT for use in highly abrasive, low-impact applications where bushing wear is severe such as sand and dirt. CELT comes standard with open center shoes.
Undercarriage wear is a fact of life. Fortunately, by adhering to the practices described, as well as conscientious operating, regular inspections and preventative maintenance, an operator can control wear and maximize undercarriage life.
For more information, visit www.casecorp.com.