There is a general consensus that while excavator undercarriage accounts for approximately 15%-20% of the cost of the machine, it usually accounts for around 30%-50% of the repair costs over its lifetime.
While undercarriage wear is unavoidable, there are a number of things an operator can pro-actively do to increase the life of its components, thereby reducing the machines per-hour operating costs and reducing the risk of significant damage and repairs.
This proactive approach can be broken down into two areas; Good Operator Practices and Regular Review and Maintenance.
Good Operator Practices
Operators should endeavour to handle the excavator with reasonable care at all times. This includes good usage of the tracks. Where possible the operator should:
- Avoiding high ground speeds;
- Avoiding track spinning;
- Avoid counter rotation;
- Avoid continual turning in the same direction;
- Avoid digging over the sprockets (dig over the idler); and
- Avoid travelling in reverse or travelling with the sprockets in front of the machine.
Excessive travelling in reverse or moving forward with the sprockets at the front of the machine creates additional internal stresses and tightening on the track parts which will cause accelerated wear. Travelling in reverse also requires additional power, which in-turn increases your fuel consumption and hourly operating costs further.
Regular Review and Maintenance
Operators should review the condition of their undercarriage on a regular basis, before, during and after operating the excavator by conducting a visual walk-around. The operator should be looking for:
- Debris caught in the tracks and rollers which can lead to increased wear rates, perceived lower power and increased fuel usage;
- Chipped, broken or sharp sprocket teeth, or loose/missing sprocket bolts;
- Missing, loose or damaged parts of the track undercarriage including the top and bottom rollers, and any track shoe bolts or guides;
- Unusual or uneven track wear;
- Oil leaks on the final drive; and
- Damage to track shoes.
- While having one bent track shoe may not appear to require immediate action, left un-repaired, that shoe will have a knock on effect to its neighbouring track shoe which then in turns affects its neighbouring shoe and so forth resulting in a costly repair job.
Excavator Undercarriage Track Tension
An important maintenance review should be the regular checking of the track tension. This should be conducted in the operating conditions of the machine, as tension levels may change dependent on hard or soft ground conditions.
If the tracks tension is too tight it may cause the components to wear at an increased rate, and if they are too loose, there is the risk that they may come off during a turn or while travelling on uneven ground.
As a general rule, tracks should be slacker in soft or muddy conditions, and tighter in rocky or harder ground conditions, however you should always consult the manufacturer’s specific operating manual for the machine in use to obtain detailed tensioning levels and instructions on adjusting the track tension.
It is recommended further to the regular daily review of your undercarriage to also have it professionally reviewed on a periodic basis. During this review the trained mechanics may complete a pin-and-bushing turn, where the track pins and bushes are rotated through 180°. Avoid letting the machine sit parked up for long periods of time.
At least once per couple of months run the machine and exercise the tracks to ensure track pins do not seize up and cause additional wear and damage. You may also consider looking at more advanced measuring tools including telematics to track actual operating usage and movement of the machine, notifying the maintenance team of things such as excessive operation in reverse which could prompt an additional review of the undercarriage health.
While an excavator undercarriage contains moving components and are classified as wear-items, taking some time to conduct appropriate operation and proper maintenance will extend the life of these expensive components and reduce chances of time-consuming repairs and replacements.