A proper undercarriage management and operations following the best practices will always help in maintenance and long life of crawler tracks. Saibal Mitra, Dy General Manager Parts Sales & Operations, Tractors India Pvt Ltd, elaborates on the causes of wear affecting the assembled track components and the best practices in operation and maintenance of crawler tracks.

What are the causes of wear and tear that most frequently affect track components?
Undercarriage is an assembly of various parts which helps a track-type machine to move. In this motion, there can be several causes of wear affecting the assembled track components. The most common types are:

• Track Tension: The tension in the link assembly to be optimum. A too tight or too loose track is a sure cause of wear for links, sprockets, rollers and even shoes.
• Shoe Width: It is important to select the correct shoe width to match the application of the machines. Improper selection can quickly wear out the shoes and even cause link breakage.
• Machine Operator: Manoeuvering a track-type machine is not an easy task. The operator must be skilled enough to operate in different conditions and thus can add life to undercarriage.
• Travel: Undercarriage is not designed to travel much. For longer distances, it is not recommended to march the machine on tracks as it will reduce life of undercarriage
• Underfoot Conditions: The machines may need to run over several underfoot conditions - abrasive, high impact, heavy moisture etc, when at work. Each of these conditions severely affects the undercarriage life to a great extent. In short, the life of an undercarriage is affected by man, machine and material.

What are the physical measurements carried out to determine the extent of wear of each element of the track assembly?
The first and foremost is daily visual checks and walk-around inspection. Any change in track adjustment, oil leaks on links, rollers and idlers, broken or loose undercarriage components or bent track shoes can be easily seen during these inspections.

For an in-depth study of the extent of wear, Custom Track Service (CTS) is used by all TIPL engineers and undercarriage specialists. CTS is recommended by Caterpillar for all its dealers such as TIPL, and is considered to be one of the best instruments to measure the extent and progress of wear and thereby taking necessary repair or replacement actions for undercarriage components. There are manual measurements tools as well as ultrasonic measurement tools for accurate measurements and estimating wear.

How do you ascertain the balance life available?
Undercarriage generally works on two limits of wear; Service Limit - 100 per cent worn and Destruction Point - 120 per cent worn. Service limit projection = current hours on undercarriage/percentage worn; Destruction point projection = service limit projection x 1.2.

There are many case studies available with TIPL where through regular CTS inspections, undercarriage life has been extended with adjustment and replacement of few components, which if neglected may have led to complete undercarriage replacement.

What are the methods for extending the life of crawler tracks?
As we have described earlier, each component of undercarriage is critical for its performance. Each component can have its own wear pattern as they operate under stress and difficult underfoot conditions.

For the track only, we have to be careful that it has the correct track tension. Too tight track affects seal integrity and increased bushing wear whereas a track that is too loose causes wear on track roller frame and increased track slap. Proper operating techniques help in extending life of undercarriage. Unproductive high-speed and travel in reverse for too long need to be avoided to prevent premature wear. Correct idler height must be maintained as it causes a host of problems like uneven wear, link scalloping, and ride vibrations.

What are the best practices in operation and maintenance of crawler tracks?
A proper undercarriage management and operations following the best practices will always help in maintenance and long life of crawler tracks. As a Cat? dealer, at TIPL, some that we recommend are:

• Daily walk-around inspection: It is the key to pick up small problems like track tension, oil leaks, broken or loose components, bent shoes, which if not attended in time can cause major damage and wear of related components in future.
• Regular cleaning of track frame to remove any deposit of foreign abrasive particle that may cause link wear during motion.
• Regular CTS with ultrasonic wear indicator tools is indispensable as it indicates the service life expected.
• Operating techniques play a vital role in crawler track performance. ?Big load slow? concept must be followed. Ideal motion has to be selected by the operator depending on load and underfoot condition. Minimum time needs to be operated in reverse direction while unproductive high speed is always best to avoid.

Even constant turning in the same direction has to be avoided as much as possible. What are the procedures and systems for rebuilding or refurbishing a track assembly? What are the facilities required for such repair jobs?
Rebuilding or refurbishment of a track assembly depends on the wear of the components. If the shoes have worn out, the old link assembly can be fitted with new shoes. Sometimes, it is the bushing turn with replacement of the sprocket only while other components are reused.

The facilities that are generally required for the above purpose is a track press, submerged arc welding machine, oil charging pump, torque runner, facility for painting and general workshop tools.

TIPL has the requisite facility to rebuild or refurbish any undercarriage completely or its components. We have the capability and experience to perform shop repairs on all undercarriage components including rebuilding links and idlers, re-shell rollers and re-grouser track shoes. We also offer complete undercarriage rebuilding and exchange with genuine Cat parts at a reasonable cost.

Any other aspects you would like to share?
Unless properly maintained, the cost of undercarriage maintenance can go as high as 50 per cent of a customer?s total maintenance cost. So, it is advisable to take help of the experts right from the selection of the proper undercarriage for machine and application. It is always recommended that during the useful life, the undercarriage experts should do the maintenance and management so that customers get the lowest cost per tonne. Cat dealers such as TIPL are trained on selection of undercarriage, maintenance management and are backed with Caterpillar?s innovative line of undercarriage offerings providing right selection, be it with any load or any underfoot condition.

Unless properly maintained, the cost of undercarriage maintenance can go as high as 50 per cent of a customer?s total maintenance cost. So, it is advisable to take help of the experts right from the selection of the proper undercarriage for machine and application.