굴착기 Hyundai R305LC-7 ,R305-7용 최종 구동장치 Jeil JMV155/89 31Q8-40030

R305LC‑7 R305‑7 Final Drive for Hyundai Excavator spare parts 31Q8‑40030 Axial Piston Motor Aftermarket

Product Overview

The Hyundai R305LC‑7 and R305‑7 are 30‑to‑33‑ton excavators that spend their days on bulk earthmoving, quarry loading and large‑scale site grading — machines where the final drive under each track takes a real pounding. The axial piston motor and planetary reducer carrying part number 31Q8‑40030 is what turns hydraulic flow into the slow, high‑torque rotation pulling these heavy frames across rutted, uneven ground. On a machine this size, drive wear announces itself across the whole operation. One track lags, the machine wanders on level ground, the drive housing runs hot after a shorter run than it should, and a deepening note comes from the track motor. Continuing to work only scores the piston group and reduction gears further. This aftermarket drive reproduces the original motor‑and‑reducer pairing as one sealed, tested unit, covering both the R305LC‑7 and R305‑7, so the worn assembly comes off and the new one bolts straight back on.

Core Advantages

1. One reference covers both R305 variants
Because this drive fits the R305LC‑7 and R305‑7, workshops maintaining Hyundai heavy fleets can stock a single unit and cover both machines. That simplifies cross‑reference when the old nameplate has worn away.

2. Torque output matched to a 30‑ton machine
These excavators carry real weight and meet real resistance on grades and broken ground. Hardened gears and piston surfaces hold the sprocket torque the tracks need to push and climb, without the laboured travel that undersized replacements produce.

3. Sealed for long hours on quarry sites
Heavy Hyundai machines work through long shifts in quarry dust, mud and standing 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 matched, tested 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. Aftermarket value for a high‑hour heavy excavator
An original Hyundai final drive exchange carries a serious price. This aftermarket unit restores track mobility at a fraction of the cost, with sample and batch supply for workshops keeping several R305 machines on the books.

Manufacturing & Quality Control

Each drive is built under controlled conditions: incoming material verification, precision machining of housings and gears, case hardening of wear surfaces and clean assembly. Before packing, every unit runs on a test bench to check output torque, internal leakage and running noise, and only passing assemblies are released. Preservation coating, moisture sealing and shock‑absorbing crating protect the drive during long‑distance transport.

Frequently Asked Questions

Q1: Does this drive fit both the R305LC‑7 and R305‑7?
A: The 31Q8‑40030 reference covers both variants, but build differences can occur. Please share your machine model and serial number so we confirm the correct unit 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 fail to pull 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 Hyundai service manual for fitting and bleeding.