Kubota mini excavators in the KX and U series run a compact undercarriage loop — rubber tracks, rollers, idler, sprocket, and hardware — matched by model generation and serial number. The parts guide for Kubota machines covers the track fitments, the steel parts, and the cross-references that keep a compact machine working. For a Quebec contractor running Kubota equipment, the undercarriage is the highest-wear system on the machine.
Related reading: for the fitment hub, see our rubber track fitment guide, and for the mini-excavator parts map, see our mini excavator guide.
*Brand names and OEM part numbers are used for identification and cross-reference only. AFT Parts is an independent aftermarket supplier unless otherwise stated.*
KX and U-Series Overview: Two Families, One Fitment Logic
Kubota's KX and U series span the mini excavator class, and both families use the same fitment logic: a rubber track loop over rollers, idler, and sprocket, with each component matched to the machine's weight and drive.
The two families differ in size range and configuration, and the parts are matched per model generation. The serial number settles which configuration the machine runs, because the same model name can carry different undercarriages across years.
Rubber Track Sizes for Kubota Models: Width, Pitch, Count
Kubota excavator tracks are matched by width, pitch, and link count, with the size code on the old track as the fastest confirmation. The track drives through the sprocket, so the pitch has to match the drive.
Confirm the track size against the model generation and the serial number before ordering. A Kubota track that is right in width but wrong in pitch will skip on the drive and wear the sprocket.
Rollers and Idlers for Kubota Excavators: Position and Part Number
Kubota bottom rollers and carrier rollers are matched by diameter, flange style, and mounting, and the front idler sets the track line. Each position in the undercarriage uses a matched part.
Identify the steel parts by position and part number, and inspect for the compact-machine pattern: roller flats, weeping seals, and idler flange wear. Replace the worn positions with the track change where the wear readings align.
The steel parts on a compact machine wear by the site: urban work shows seal wear and flats from varied duty, while abrasive sites show flange loss and profile wear. Reading the pattern tells the mechanic whether the part is reporting on the machine or on the ground, and the two need different replacement timing.
Reading Kubota Part Numbers
Kubota part numbers identify the component family and configuration, and the number is read from the part or the parts book. Photograph the old part number before removal and cross-reference it with the supplier.
Cross-check the part number with the machine serial number, because the model name alone does not settle the configuration.
The photograph matters because Kubota numbers are stamped into the part and can be worn or painted over by service. A photo taken before removal captures the number the parts book can match, and it saves the measuring and cross-referencing that a missing number forces.
Aftermarket Options and Warranties: Compare the Spec in Writing
Quality aftermarket Kubota parts match the OEM specification: dimensions, material, hardness, and bolt pattern. Compare the documented spec and the warranty, and confirm the fitment against the serial number before dispatch.
For a compact machine, the aftermarket case is strongest where the OEM number is established and the machine is out of warranty. The written comparison is the buying record.
The comparison should also cover the part's intended duty: a Kubota that works urban surfaces every day needs the standard spec, while one that works abrasive fill needs the heavy-duty option documented. Matching the spec to the machine's actual work is what makes the aftermarket part a replacement rather than a compromise.
Building a Kubota Replacement Plan
The Kubota replacement plan follows the wear log: track, rollers, idler, and sprocket readings per machine, with the parts ordered ahead of the threshold. The plan keeps a compact machine to one maintenance stop.
Confirm the part numbers and the delivery window against the maintenance schedule, and keep the fitment confirmation with the machine record.
The plan also covers the hardware line: roller bolts, idler hardware, and the seals that fail with every change. Ordering the hardware with the parts keeps the stop to one delivery, and it is the line that piecemeal buying usually misses.
| Kubota fitment field | What it settles |
|---|---|
| Machine model and generation | The undercarriage family |
| Machine serial number | The exact configuration |
| Old part number or size code, photographed | The component cross-reference |
| Position in the undercarriage | The right part for the position |
| Cross-reference against the serial number | The aftermarket match |
See the Rubber Track collection and the Track Roller collection for your Kubota machine.
Conclusion
Kubota KX and U-series undercarriages are matched by model generation and serial number: confirm the track size code, identify the steel parts by position, and compare aftermarket parts on the documented spec. The plan that follows the wear log keeps the compact machine to one stop.
Questions to Ask Before You Order
- What track size and pitch does my Kubota serial number use?
- Which roller, idler, and sprocket part numbers apply?
- Is the aftermarket specification compared in writing before dispatch?
Frequently Asked Questions
Which Kubota models share track and roller parts?
Sharing is strongest within the same family generation, such as related KX models or related U-series machines. The serial-number parts book settles which parts cross between models.
Where is the Kubota part number read on the machine?
The number is stamped into the part or listed in the parts book. Photograph it before removal, because service wear can make it unreadable later.
What is the most common Kubota misorder?
The track pitch is the usual mistake: a track that is right in width but wrong in pitch skips on the drive. Confirm the size code and pitch together before ordering.