Excavator
Undercarriage Parts
The undercarriage system, explained — what each part is called, how to identify it, and what wear looks like.
The undercarriage system, explained — what each part is called, how to identify it, and what wear looks like.
The six components that make up the system, from the top of the frame down.
Also called the top roller. Supports the upper, return run of track between the idler and sprocket.
The linked steel chain the machine runs on — separate from the shoe bolted to it.
The flat plate bolted to each chain link that contacts the ground.
Also called the track roller. Carries the machine's weight along the lower frame.
Guides the chain at the front and works with the track tensioner.
Drives the chain. Wears together with the chain and idler.
Trade names vary — here's what we recognise, and what we need to match it.
| Part | Also Called | What to Send |
|---|---|---|
| Track Chain | Chain / Track Link Assembly | Machine model + side photo + part number |
| Bottom Roller | Track Roller / Lower Roller | Model + mounting photo |
| Carrier Roller | Top Roller | Model + photo |
| Idler | Front Idler | Model + photo / measurements |
| Sprocket | Drive Sprocket | Model + tooth/rim photo |
| Track Shoe | Track Plate | Width + bolt pattern |
A general visual reference, not a diagnosis — a mechanic should confirm before you order.
