The most important Undercarriage Inspection is the End-of-Life inspection where the undercarriage components have reached the end of their useful life. This vitally important inspection is typically missed by most inspectors.
So why is this inspection and the data so valuable.
Undercarriage residual life is normally determined through inspection where the measurement of the remaining material indicates the percent worn and facilitates the calculation of the residual hours available in the remaining material based on the hours already logged against the component since new.
Recording the end point in % Worn provides a complete history of the component.
- This enables a correct cost per hour to be calculated
- Recording how the Undercarriage Component failed is important. This can be useful to determine how often this failure mode occurs so that greater life can be extracted out of the components by early recognition of these early onset failure modes
- Recording the % worn will indicate how much of the component life is possibly being thrown away because there is still wear material available.
- All the components together with end of life % worn is an indication of how well the undercarriage has been managed over its life. The objective is to try and have all components achieve 100% worn at about the same point.
- It will also indicate whether the Wear Limits are suitable for the application.
- It will also indicate what is truly a worn-out component, and what is the percentage worn for this point. The general practice at present is to use the OEM limits to determine 100 and 120% worn, but maybe the components can be taken beyond this point without too much risk. Every hour extra that the component life is extended, the lower the cost per hour.
- It will show whether correct decisions have been made achieve full undercarriage life and if not, what is the best course of action in the future based on knowledge obtained
- Whether the shoes were the correct width for the application
- Turning the bushes at about the correct point in time
- Resealing was effective to extend chain life
- If Fitting new shoes or re-lugging is the best option
- Whether rollers should be swapped midlife
- Whether the undercarriage is performing as advertised for the application
Mistakes will be made, but through these mistakes comes knowledge!
For all those Undercarriage Inspectors and Reliability Teams out there, consider this last inspection as the most important for the information it can provide!