On a hydraulic excavator, the "final drive" isn't one part — it's a family of gearboxes that turn hydraulic power into the machine's mechanical movement. The two you'll hear about most are the travel gearbox and the swing gearbox. They look similar, they do similar jobs, but they're not interchangeable. Order the wrong one and it won't bolt up.
Here's how to tell them apart.
What a travel gearbox does
The travel gearbox drives the boom / stick / arm — the long section that reaches out and digs. "Travel" refers to the boom moving through its range (raise, lower, extend). On many machines this is also called the boom gearbox or dig arm gearbox. It's the gearbox closest to where the hoist cylinders act on the boom.
What a swing gearbox does
The swing gearbox drives the rotation (slewing) of the cab/house — turning the whole upper structure of the machine left and right. "Swing" = the swing of the cab. Some markets call it the rotation gearbox or slew drive. It sits lower, under the house, and carries the unit's rotation load.
Quick way to tell them apart on the machine
- Travel / boom gearbox — mounted up in the boom area; its function is lifting and reaching.
- Swing / rotation gearbox — mounted under the cab; its function is rotating the house.
- Look at which cylinder or motion it controls: up/down & reach = travel; left/right rotation = swing.
- Photos from the machine (or your old unit) remove all doubt — send them and we'll match it.
Side by side
| Travel / Boom gearbox | Swing / Rotation gearbox | |
|---|---|---|
| Function | Boom lift & reach | Cab rotation (slew) |
| Location | Boom area | Under the cab/house |
| Also called | Boom, dig-arm gearbox | Rotation, slew drive |
| Wrong match result | Won't bolt up / wrong motion | Won't bolt up / wrong motion |
Send a photo or the part number — we'll identify travel vs swing and quote the right unit.
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Why it matters for ordering
Travel and swing gearboxes for the same machine can have different part numbers, gear ratios, and mounting. When you search our catalogue, knowing "travel" vs "swing" instantly cuts the possibilities in half — and it's the difference between a part that fits and one that sits on the shelf while your machine is down.