Crawler excavators are machines that must face extreme conditions in their daily work.
In the event of a failure, every hour of downtime translates to real losses for the owner. Therefore, quick diagnosis and repair are crucial. Using the example of the Doosan DX 225LC excavator from 2014, we will show how to repair a damaged track tensioner and replace the idler wheel.
Causes of the track problem
In this case, the problem occurred in the track tensioner. This component is responsible for maintaining the proper tension of the track, which ensures the stable operation of the machine. Unfortunately, the seals were already worn out, and the grease, instead of pushing the piston and keeping the track tight, was leaking out the side. As a result, the track was loose and often fell off the guides.
Such symptoms are extremely troublesome for the operator – they force frequent topping up of grease, and if neglected, the machine becomes practically unusable. Regular inspections of the condition of the tensioner and track guides are the best way to avoid similar problems in the future.
Disassembly and diagnosis of the tensioner
After disassembling the tensioner, it turned out that the main seal was damaged, and the piston itself was heavily corroded. Such wear means that even replacing the seals alone would not guarantee proper operation. Therefore, a complete replacement was necessary. During the inspection, it was also noted that the idler wheel was heavily worn and cracked – this component also required replacement.
Why are seals so important?
The seals in the tensioner are responsible for maintaining the pressure of the grease, which pushes out the piston and tensions the track. If they become damaged, the grease escapes outside, and the track becomes loose. Consequently, this leads to it falling off and accelerated wear of the entire drive system.
Installation of the new tensioner and wheel
After consulting with the client, a decision was made to replace the entire set: the tensioner along with the wheel. New parts were prepared for installation. The process included:
- correctly positioning the tensioner,
- installing the idler wheel,
- placing the track on the guides,
- tensioning the track with grease.
After completing the work and starting the machine, a test was performed – the track was properly tensioned, did not fall off, and laid evenly on the guide wheels. As a result, the Doosan DX 225LC excavator could return to work the same day.
Why is quick response important?
A damaged track tensioner is not just a problem with the machine's operation. A falling track can cause additional damage – deformations of the guides, accelerated wear of the rollers, or damage to the wheels. Moreover, every hour of downtime for the excavator incurs financial losses. In this case, the quick replacement of the entire repair set allowed avoiding prolonged failure and costly repairs in the future.
Summary
The repair of the track on the Doosan DX 225LC excavator demonstrates how essential regular inspection of the components of the drive system is. Worn seals, a corroded piston, or a cracked tensioner wheel are signals that action must be taken quickly. Thanks to the comprehensive replacement of the entire tensioner along with the wheel, the machine regained full functionality and could return to the construction site without unnecessary downtime.
By ensuring proper servicing of excavators, operators can avoid many problems related to operation. Regular inspections and quick responses to the first signs of failure are the key to the reliability of construction machines.
