Undercarriage parts
that is where its life is decided, not in the thickness of the metal.
Illustration based on an existing product.
Rollers, sprocket, idler, tensioner.
They are what makes the track turn, and it is their wear that decides how long everything else lasts.
Other names for this part: bottom roller, top roller, sprocket, idler, tensioner, recoil spring, track undercarriage.
- Family
- Wear parts
- Classes or machines concerned
- All
- Fitting
- As an original-equipment replacement (undercarriage part)
- Power source
- None
What it is for
Right: a new sprocket on a worn chain, which will wear out in a short time.
What sets it apart:
the same excavator model can take two undercarriages depending on the year — the serial number settles it.
Computer-generated image.
it is the moment when replacing it costs the least.
Synthetic image.
The undercarriage carries, guides and drives the track.
The sprocket drives it, the idler sends it back, the rollers carry it, the tensioner keeps it under tension.
These parts wear slowly and together.
That is why they are not judged one by one:
a new sprocket on a stretched chain wears out in a few hundred hours.
The most frequent cause of premature wear is not the ground, it is the tension. Too tight, the track eats the sprocket and the rollers.
Too slack, it comes off and slaps.
The setting is checked, it is not guessed.
On which machine?
Undercarriage parts are fitted to replace the original parts.
They suit machines from 0,5 to 65 t.
What the tool does
They include, in particular, rollers, sprockets and idlers.
For a mini-excavator, a top roller weighs 2 kg and a bottom roller 4 kg.
A mini-excavator sprocket weighs 7 kg, an idler 10 kg.
What is needed on the hydraulic side
They need no hydraulic connection: they are parts of the machine.
Figures taken from 6 models on the market.
Your study sets the exact value for your machine.
Have your machine checked.
Tell us the model and the serial number of your machine, and what you are seeing:
the track coming off, noise, a leak, a track that slaps.
- Your machine Its exact make and model.
- What is fitted What equips the machine today.
- The work What the machine is used for.
Without these details, the study still begins: we will ask you for them.
Or call 01 84 16 55 49 · our lines are open 7 days a week, from 7h to 22h.
Written study within 3 working days, once the file is complete.
What determines the choice
-
01 — The undercarriage, not the commercial model
The same excavator model can take two different undercarriages depending on the year.
The serial number settles it. -
02 — The sealing of the rollers
A roller that leaks is a finished roller.
The quality of the seal makes the life, not the thickness of the metal. -
03 — The stage of wear of the whole
You replace in coherent sets.
Mixing new parts with very worn ones shortens the life of both. -
04 — The downtime you can accept
A complete undercarriage means several days in the workshop.
That is planned out of season, not in an emergency.
What is checked before ordering
- Record the machine's serial number, not only its model:
undercarriages change part-way through a production run. - Look at the shape of the sprocket teeth:
symmetrical, they are good; hooked, they are finished. - Look for oil traces under the rollers — a leak condemns the roller even if it still turns.
- Measure the sag of the track before concluding that it is worn:
a badly set tension mimics every symptom.
- Family
- Wear parts
- Compatibility
- The seven criteria in detail →