3063958 Final Drive Sun Gear 25T for Hitachi EX200-3 EX200-5 ZX200

3063958 Final Drive Sun Gear

The 3063958 sun gear is a replacement gear used inside the planetary reduction section of an excavator final drive and travel gearbox.

It engages with the surrounding planetary gears and helps transmit rotational force through the reduction system as the travel gearbox reduces speed and increases output torque.

Accurate tooth geometry, correct gear engagement and stable alignment are important for smooth power transmission and reliable travel system operation.

Function in the Travel Reduction Gearbox

The sun gear is positioned at the center of the planetary gear system. During excavator travel, rotational force passes through the sun gear and surrounding planetary gears as the reduction gearbox converts higher rotational speed into increased travel torque.

Because the gear operates under continuous load and repeated tooth contact, wear on the gear teeth or internal bore can affect alignment and reduce the reliability of the final drive.

The sun gear should be inspected when symptoms such as the following are found:

• Abnormal grinding or whining noise from the final drive

• Visible wear, chipping or pitting on the gear teeth

• Metal particles in the final drive oil

• Excessive backlash in the planetary gear system

• Weak or unstable travel performance

If abnormal gear wear or tooth damage is found, the surrounding planetary reduction components should also be inspected before the travel gearbox is reassembled.

What to Check Before Replacement

Before installing a replacement sun gear, inspect the original component for tooth wear, cracks, surface pitting and abnormal contact patterns.

The internal bore and mating surfaces should also be checked for wear or deformation that could affect alignment inside the final drive.

The condition of the final drive oil should be checked at the same time, especially if metal contamination or unusual noise was present before disassembly.

Ordering and Fitment Verification

To help confirm the correct sun gear before ordering, please provide one or more of the following:

• Excavator brand and model

• Machine serial number

• Original part information

• Final drive or travel device information

• Clear photos of the original gear

• Gear diameter, bore size and tooth count when available

Comparing the original gear and confirming the travel device configuration before ordering helps reduce the risk of selecting an incorrect replacement.

Why Source Final Drive Gears from Topvelsun

Topvelsun supplies replacement excavator final drive, travel motor and planetary reduction components for major construction equipment applications.

We can assist with machine application verification and component matching to help customers select the correct replacement gear for final drive repair and maintenance.

Send us part number 3063958 together with your excavator information to request availability and quotation.