Gearboxes

Gearboxes for Excavators, Construction Machinery and Industrial Equipment

Hydraulic gearboxes and mechanical reduction gear units are essential components used to transfer torque, reduce rotational speed and increase output force in construction machinery, excavators, industrial equipment and mobile drive systems.

HPM Hydraulic supplies travel gearboxes, swing gearboxes and industrial gearboxes for replacement and repair applications. Our catalogue includes gearboxes identified by OEM numbers, machine models and technical references.

Types of Gearboxes Available

Travel Gearboxes

Travel gearboxes are used in excavators and crawler machines to transfer torque from the hydraulic travel motor to the drive sprocket. They are often part of a complete final drive assembly.

Swing Gearboxes

Swing gearboxes transfer torque from the hydraulic swing motor to the excavator swing mechanism, allowing controlled rotation of the machine upper structure.

Industrial Gearboxes

Industrial gearboxes are used in machinery and drive systems where mechanical speed reduction and torque multiplication are required.

How Does a Hydraulic Gearbox Work?

A gearbox reduces the rotational speed delivered by a hydraulic motor while increasing output torque. Many construction-machine gearboxes use planetary gear stages because they provide high torque capacity in a compact housing.

Typical gearbox components include:

• planet gears,
• sun gears,
• ring gears,
• planet carriers,
• bearings,
• shafts,
• seals and retaining components.

How to Select the Correct Gearbox

A replacement gearbox must match the original machine and drive system. External appearance alone is not sufficient for correct identification.

Check:

• machine manufacturer and model,
• OEM number,
• gearbox manufacturer and reference,
• reduction ratio,
• input shaft dimensions,
• output flange or sprocket interface,
• mounting pattern,
• motor compatibility.

OEM Number and Machine Model

The OEM number and machine model are usually the safest starting points when selecting a replacement gearbox. Similar-looking units may have different internal ratios, mounting dimensions or shaft configurations.

Reduction Ratio

The reduction ratio determines the relationship between motor speed and gearbox output speed. It also affects output torque. A replacement gearbox should match the original ratio unless the drive system has been specifically engineered for a different configuration.

Common Symptoms of Gearbox Wear

• abnormal mechanical noise,
• excessive backlash,
• oil leakage,
• reduced drive performance,
• vibration,
• overheating,
• metal particles in gearbox oil,
• difficulty transferring torque.

Gearbox problems can also be related to hydraulic motors, bearings, mounting components or insufficient lubrication, so complete diagnosis is recommended before replacement.

Replacement Gearboxes from HPM Hydraulic

HPM Hydraulic supplies replacement gearboxes and final drive components for excavators, construction machinery and industrial applications.

If you are unsure which unit fits your machine, provide the machine model, OEM number, gearbox reference and photographs of the original component.

Gearboxes and Hydraulic Drive Components

Hydraulic gearboxes work directly with motors in travel, swing and industrial drive systems. Browse our excavator travel motors and swing motors for related hydraulic drive components.

For gearbox rebuilding, see our hydraulic and gearbox spare parts.

FAQ – Gearboxes

What is a gearbox used for in an excavator?

A gearbox reduces motor speed and increases torque for travel or swing functions.

What is a planetary gearbox?

A planetary gearbox uses a sun gear, planet gears and ring gear to provide high torque multiplication in a compact design.

How do I identify the correct replacement gearbox?

Use the OEM number, machine model, gearbox reference, reduction ratio, mounting pattern and shaft dimensions.

Can two similar-looking gearboxes be interchangeable?

Not necessarily. Internal ratio, shaft dimensions, bolt pattern and motor interface may differ.