Hitachi HMGE20 4405308 Fahrantrieb für Hitachi EX135 Midibagger

EX135 Final Drive for Hitachi Excavator spare parts 4405308 HMGE20 Axial Piston Motor OEM

Product Overview

The Hitachi EX135 sits in the useful middle ground — bigger than a compact excavator, lighter than a 20‑ton machine, and well suited to roadwork, utility trenching and site grading where a full‑size excavator would be overkill. The axial piston motor and planetary reducer under each track, carrying part number 4405308 and drive model HMGE20, is what moves it: turning hydraulic flow into the slow, torque‑rich rotation that pulls the machine across uneven ground. On this class, drive wear tends to show up first as a subtle mismatch between the two tracks — one lags, the machine drifts on level ground, the drive housing warms faster than its opposite. Left unattended, it progresses into a side that hesitates rather than pulls, and by then the piston group and gears are scoring against each other. This OEM‑grade drive reproduces the original HMGE20 motor‑and‑reducer pairing as one sealed, tested assembly, so the worn unit comes off and the new one bolts straight back on.

Core Advantages

1. OEM‑grade internal clearances for even track pull
The piston, cylinder block and valve plate are finished to tight tolerances, so hydraulic pressure does not leak away inside the unit. Both tracks then push in step — no drifting, no slow side, no hesitation the moment the bucket loads up.

2. Hardened gears for a mid‑size machine's daily duty
The planetary gear set is case‑hardened and precision‑cut with controlled backlash. Meshing stays smooth and quiet, the drive torque spreads across the teeth, and wear from years of track push and ramp climbing slows right down.

3. Sealed for long hours on mixed site conditions
Roadwork and trenching sites expose the drive to dust, mud and water. Fitted output‑shaft and housing seals keep grit out of the motor and reducer — the protection that decides whether the drive lasts its service life.

4. One tested, matched unit for a clean swap
Motor and reducer arrive pre‑assembled and bench‑checked, so the fitter removes the old drive and bolts on the new one without sourcing separate components. No mid‑job mismatches, no second visit to chase a leak.

5. OEM‑spec quality at a practical repair cost
Renewing the drive to OEM grade restores the EX135's mobility far below the price of an original exchange unit, with sample and batch supply for workshops maintaining Hitachi mid‑size machines.

Manufacturing & Quality Control

The OEM‑grade route follows controlled specifications: material certification, precision machining of housings and gears, case hardening of wear surfaces and clean assembly. Each completed drive runs on a test rig to verify output torque, internal leakage and running noise before release, and only passing units are packed. Full preservation coating, moisture sealing and shock‑absorbing export casing protect the assembly during transport.

Frequently Asked Questions

Q1: How do I confirm 4405308 matches my EX135?
A: Compare the reference on your existing drive and share your machine serial number. Hitachi build variants can differ, so we verify before dispatch.

Q2: Is this the complete motor and reducer?
A: Yes — the listing covers the full axial piston motor and planetary reducer as one assembly, ready to bolt on. Separate components can be checked on request.

Q3: What faults point to drive wear?
A: Uneven track speed, drifting on flat ground, a hot or noisy track motor and tracks that hesitate under load. Inspect early, before debris spreads through the travel circuit.

Q4: What is the warranty position?
A: Manufacturing and material defects are covered. Damage from contaminated oil, debris in the motor, track obstruction, overload or incorrect installation is excluded; follow the Hitachi service manual for fitting and bleeding.