Rules of Replacement

In rough jobsites around the country, the vulcanized rubber tracks on a mini excavator certainly take a beating. Whether it’s working through harsh weather conditions or maneuvering over aggressive grounds, good tracks will continue to roll through obstacles to dig, backfill, break, pick and place and handle every task faced by a hardworking mini digger.

There are three types of tracks available for mini excavators: rubber, steel and hybrid tracks. Rubber tracks are by far the most popular on compact excavators and feature continuous rubber belt tracks with steel or iron cores embedded within. The tracks are held together by cables which are also embedded inside. Rubber tracks are an all around track, ideal for areas that are sensitive, but with the ability to traverse most grass, ground or concrete jobsites. For example, rubber tracks work well in landscape applications when they must move across both green space and concrete. The cost of rubber tracks can vary significantly, says Chris Ono, customer relations manager for McLaren Industries.

Some major OEM manufacturers of rubber tracks include McLaren Industries, Bridgestone, DRB America and Solideal.

Steel tracks are recommended for use in harsh environments such as jobsites that feature rocks and other debris that may harm rubber tracks. However, steel tracks can damage asphalt, concrete and landscaping. Like rubber, the cost of steel tracks varies. Berco is one of the manufacturers of steel tracks.

Hybrid tracks are the combination of the steel track style with bolt-on rubber pads. This type of track offers the strength of steel mixed with the benefits of a rubber track — such as a smooth ride, less damage to asphalt and concrete surfaces and reduced downtime. McLaren is a manufacturer of hybrid tracks.

“The other method for obtaining hybrid tracks is to purchase the rubber pad attachment for the steel track and then bolt on or secure these rubber pads to the steel tracks,” says Ron Waters, rubber track aftermarket sales specialist for DRB America. “These pads can range from $10 to $49 or even more per pad and each track on a large machine may require 100 pads or so.”

However, when a mini ex track becomes damaged or worn, there’s no Band-Aid approach to maintaining your track system. Most times the tracks need to be replaced, which is not a cheap endeavor, costing anywhere from $300 to $3,000. But by knowing the warning signs of track replacement, how to select the right track for your compact excavator and how to care for that track during the work week, crews can avoid dreaded downtime and extend track usability to its maximum lifespan.

By conducting a simple track inspection after each work day, an operator can evaluate the wear the tracks have accrued over each job and jobsite. One of the most common checks is to focus on the track’s tread pattern and its depth. If the pattern is nearly worn out or almost smooth, the track should be replaced since it will most likely not achieve the traction it needs to perform efficiently.

Beyond normal wear and tear the tracks may experience from daily use, there are larger damages that can occur to a track that require a replacement immediately. A deep crack or tear in the track that expands almost halfway across the track warrants the need for a replacement, says Waters.

“When driving rubber tracks on narrow or rough roads, the sides of rubber tracks may become bent, so that cracks or rips occur,” says Waters. “Driving on rugged surfaces or a surface that has many foreign objects such as sharp stones may twist the edge of the rubber and the rubber can be cut or split.”

In order to prevent damaging a track like this, an operator should be cautious in maneuvering the machine on narrow roads, logging areas and construction areas that have broken concrete pieces.

Operators should also be aware of specific types of damage to the tracks such as separation of the steel links, broken steel cables and cuts or gashes that expose the steel cords, says Ono. Worn steel links are also a concern since they can cause the track’s pitch to be off. A track’s pitch is the distance from one guide tooth on the inside of the track to the next, and it is generally measured in millimeters, explains Ono. “When a pitch is off it means that it is not engaging with the sprocket tooth correctly — either the sprocket teeth distance or the pitch is off,” he adds.

Most manufacturers recommend that the tracks on a mini excavator should be replaced every 1,500 hours of use, depending on application. However, the life of the tracks can extend beyond that time if the tracks are maintained properly throughout their use. By being aware of the track’s condition, the work area it performs in and general upkeep like tension and pitch, an operator can increase a track’s lifespan beyond expectations.

Width, Pitch and Tread Pattern

When looking to purchase replacement tracks for a mini excavator, three track features should be considered: width, pitch and tread pattern. First, the proper width of the track should be determined to best suit the machine. The width of tracks is measured in millimeters and wider tracks offer better flotation, while narrower tracks are typically less expensive.

The pitch of the track should also be considered in the decision-making process. There are two types of pitch — long and short. Short pitch tracks engage every sprocket tooth on the track, ensuring a smoother ride, explains Ono, and long pitch tracks engage every other sprocket tooth, resulting in a slightly rougher ride. However, long pitch tracks are generally less expensive.

Finally, the tread pattern of the new track should be determined. There are two main types of tread patterns to choose from — turf-friendly or aggressive — says Waters. A turf-friendly track has more contact points with the ground so there’s less pressure. The lugs on the tracks are spaced more closely together, so the ground is less disturbed and the machine doesn’t have much impact on the ground, avoiding scarring or markings. An aggressive tread pattern may feature a zigzag pattern with sharp, prominent lugs, explains Waters. With an aggressive pattern, an operator can expect better traction on loose, wet soil conditions, but also a bigger footprint.

Both Ono and Waters suggest purchasing tracks from a reputable dealer that offers a warranty on the track and good after-sales support. Waters recommends buying the replacement track ahead of time, therefore an operator doesn’t experience as much downtime as he would purchasing the tracks when absolutely necessary.

Keeping on Track

To keep tracks in top-notch shape, the track’s condition should be checked frequently — examining the track for any cracks, tears and its tread pattern to make sure it has not worn down.

Ono also suggests owners and operators keep an eye on the terrain that the machine is running over. For example, avoiding curbs and debris, as well as sharp turns on asphalt or concrete all contributes to longer track life. If the jobsites an operator will be working on include rocks and aggressive terrain, a steel track would better fit the demands of those projects.

Waters recommends that the track’s tension should be checked every 50 hours of use. In order to do that, one side of the excavator should be lifted using the boom. At the midpoint of the track undercarriage, the track should be able to flex 10 to 15 mm to ensure proper tension. Maintaining the right tension will help extend the life of the track.

“While some people believe that keeping track tension especially tight will make it last longer, that’s not the case,” explains George Zafirov, marketing manager for McLaren Industries. “Some flex is needed, otherwise the track will react similarly to an over-inflated tire. Conversely, tracks that are too loose can eventually damage the cleats around the planetary drive wheel.”

Keeping the tracks clean is also important. Since debris may become stuck between the track and metal components of the undercarriage, washing the track with a pressure washer helps eliminate the possibility of debris grinding at the surface. By neglecting to wash the undercarriage, it can cause the recoil mechanisms to fail and a track’s cables to break, says Zafirov.

When the time comes to replace the tracks on a mini excavator, it’s important to understand the type of track that’s needed and to find one that best suits the applications the machine takes on. Knowing the right type of track that’s needed and the features that will help increase productivity, an operator can pick a new track and get back to the job with minimum downtime.

Pam Stask is assistant editor of Compact Equipment, based in Peninsula, Ohio.

Installation Insights

A Step-by-Step Guide on How to
Install New Mini Excavator Tracks

1.
Safety First: First and foremost, make sure to use the proper safety
gear when working around the machine such as gloves and protective
eyewear. This is a job recommended for two or more people.

2.
Releasing Tension: Release the weight of the excavator by lifting one
side of the machine off of the ground using the boom. Begin by removing
the panel of the undercarriage and releasing the grease that maintains
the tension. This will bring the front idler in and allow enough slack
to remove the track from the machine. Using a steel rod, roll the track
off the machine from the front idler. One person should move the track
back and forth, while the other carefully removes the track.

3.
Double Duty: While working on replacing the track, take the time to
inspect other undercarriage components such as the guide wheels, idler
and sprockets for any damage. This allows you to take care of two tasks
at once and make sure that the undercarriage components are working
properly.

4. Ready to Work: Mount the new
track and reapply the tension according to the manufacturer’s
specifications. Lower the mini excavator and the track should be ready
for use. Make sure to perform standard maintenance checks on both the
machine and its track to ensure hours of productivity.