31N8-40053 final drive for Hyundai R290LC-7 ,R290-7 excavator

R290LC‑7 R290‑7 Final Drive for Hyundai Excavator spare parts 31N8‑40053 31N9‑40010 Axial Piston Motor Aftermarket

Product Overview

The Hyundai R290LC‑7 and R290‑7 sit just under the 30‑ton class — 29‑ton Robex machines chosen for bulk earthworks, quarry loading and large site grading where a balance of dig depth and mobility matters. Under each track frame sits the axial piston motor and planetary reducer, covered by references 31N8‑40053 and 31N9‑40010, that takes high‑pressure oil from the main pump and trades speed for the low‑speed torque pulling the machine across rutted, uneven ground.

On a worked Robex ‑7, the drive wears down in ways that crews often dismiss until they can no longer. One track lags on the ramp climb, the track shell warms faster than its opposite after a few cycles, and a low note builds through the floor under reversing. Most operators keep digging — but by then the piston block and valve plate have been lapping swarf into the oil, and that debris scores every surface it touches. This aftermarket unit arrives as one sealed, bench‑run motor‑and‑reducer assembly, covering both the LC and standard undercarriage, so the worn drive lifts out whole and the new one bolts straight in.

Core Advantages

1. One range covers both undercarriage lengths
The 31N8 and 31N9 references cover the LC long‑undercarriage and standard R290‑7 builds, so workshops running a mixed Hyundai fleet keep one range on the shelf rather than two.

2. Torque to pull a 29‑ton frame up ramps
Hardened gear stages multiply motor output down to sprocket speed, so the track digs in rather than spinning on muddy climbs. No laboured, whirring travel under a full bucket.

3. A lapped piston group that holds pressure
The cylinder block, piston shoes and valve plate are finished to close clearance, so oil pressure does not bleed internally. Both tracks pull in step — no wander on the haul road, no lazy side.

4. Sealed for quarry dust and standing water
Heavy Hyundai machines work through long shifts in dust, mud and water. Fresh shaft and housing seals keep grit out of the lube — the line between a drive that lasts and one that fails early.

5. Aftermarket price for a high‑hour Robex
An original Hyundai final drive exchange carries a premium that is hard to justify on a worked R290. This unit restores full track mobility at a fraction of that cost, with sample and bulk supply available.

Manufacturing & Quality Control

Parts are machined to Hyundai print, heat‑treated at wear points, and assembled in a clean shop. Each finished drive runs on a hydraulic stand while torque, leakage and noise are logged; units outside spec are reworked before packing. The internals are fogged with preservation oil, ports are plugged, and the assembly ships on shock‑absorbing dunnage.

Frequently Asked Questions

Q1: How do I tell the LC and standard undercarriage apart?
A: The LC has a longer track frame and wider shoe spacing. If unsure, send a side photo and the serial number — we will confirm which you have.

Q2: Will this fit other Robex 29‑ton variants?
A: The R290 range shares the drive platform, but mounting and porting can differ by year. Send the machine serial number and we confirm before dispatch rather than assuming.

Q3: What break‑in should the operator follow?
A: Take the first shift easy on loaded ramps. Light cycling seats the new gears and seals, then check oil level and fitting torque after the first day.

Q4: Can I ship this by sea to African ports?
A: Yes — drives this size ship well by sea. Tell us the destination port and we will quote door‑to‑port or door‑to‑door, including any inland trucking needed.

Q5: What if the part number on my machine is different?
A: Send a photo of the old drive's ID plate and the machine serial number. We cross‑reference against our catalogue and tell you honestly whether it matches, even if that means we cannot supply it.