Bộ truyền động bằng xích Jeil JMV155 39Q8-42100 dành cho máy đào Hyundai R320LC-7 R305-7 R320-7

R320LC‑7 R305‑7 R320‑7 Final Drive for Excavator spare parts 39Q8‑42100 Travel Motor with Reduction OEM

Product Overview

The Hyundai Robex ‑7 range covers some of the brand's heaviest excavators — the R320LC‑7, R305‑7 and R320‑7 are 30‑to‑32‑ton machines built for bulk earthmoving, quarry work and large‑scale site excavation. The travel motor with reduction under each track, carrying part number 39Q8‑42100, is what gives them that mobility: an axial piston motor and planetary gearbox turning hydraulic flow into the slow, high‑torque rotation pulling such heavy frames across ground. On machines this size, drive wear is felt across the whole machine. One track lags, the machine pulls off line on level ground, the drive housing runs hot after a shorter run than it should, and a deepening note comes from the track motor. Running on scores the piston group and reduction gears further. This OEM‑grade drive is built as one matched motor‑and‑reduction assembly, covering all three Robex models, so the worn unit comes off and the new one bolts straight back on.

Core Advantages

1. One reference covers three heavy Robex models
Because this drive fits the R320LC‑7, R305‑7 and R320‑7, workshops maintaining heavy Hyundai fleets can stock a single unit and cover all three machines. That simplifies cross‑reference and shortens turnaround when a drive fails.

2. Output torque 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 Robex 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 reduction — the protection that decides whether the drive lasts its service life.

4. A complete, tested unit for fast turnaround
Motor and reduction arrive pre‑assembled and bench‑checked, so the whole drive swaps in one operation. No sourcing separate parts, no mid‑job mismatches — critical when a stationary 30‑ton machine is losing money by the hour.

5. OEM‑spec quality at a practical repair cost
An original Hyundai final drive exchange carries a premium. This OEM‑grade unit matches the original fit and performance at a more workable price, with sample and bulk supply for fleets running several of these 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: Does this drive fit all three Robex models?
A: The 39Q8‑42100 reference covers the R320LC‑7, R305‑7 and R320‑7, but build variants 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 reduction?
A: Yes — the listing covers the full travel motor with planetary reduction as one assembly, ready to bolt on. Separate components can be checked on request.

Q3: What symptoms point to drive wear?
A: Uneven track speed, pulling to one side on level 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.