Doosan DH300-7 Travel Gearbox 2nd Planetary Carrier Spider With Sun Gear Assy for Excavator Parts

This split-style secondary planetary carrier and sun gear set forms the core mid-stage reduction unit inside the travel motor final drive, specially built for Doosan DH300-7 heavy crawler excavators. Widely used in open-pit mining, large-scale earthworks, road construction and river dredging, this model endures heavy continuous loads, uphill climbing resistance and frequent rock impacts during daily operation.

The secondary planetary assembly bears frequent alternating torque and instant impact pressure. Once spider arms crack, sun gear teeth spall or internal splines wear down severely, operators will face uneven track speed, insufficient travel traction, persistent metal grinding noise and excessive heat buildup within the entire travel drive housing.

We strictly follow original Doosan factory dimensional standards for gear tooth profiles, inner spline parameters and mounting hole layouts. This assembly is a direct drop-in replacement with zero on-site cutting or reaming work, cutting maintenance downtime significantly. It perfectly solves the points of long lead times and inflated costs for genuine OEM spare parts, a common trouble for global fleets running aging DH300-7 machines across Africa, Southeast Asia and the Middle East.

1. 1:1 OEM Precision Matching Exclusively for Doosan DH300-7 Travel Final Drive

   This planetary carrier and sun gear combination is tailor-made to fit the internal cavity of DH300-7 travel reducers, with no cross-model compatibility for other Doosan excavators like DH220 or DH370. Exact repliion of original spline and gear meshing dimensions maintains ideal clearance, eliminating track deviation, unsteady walking motion, harsh internal friction noise and premature wear of matched transmission components post-installation.

2. One-Piece Thick Forged Structure Boosts Long-Term Mining Service Life

   Budget generic aftermarket planetary carriers commonly suffer broken spider arms or chipped sun gear teeth under round-the-clock heavy mining loads. Our integrated thick die forging process, paired with full multi-stage constant-temperature heat treatment, drastically improves impact resistance and fatigue resistance. It delivers steady torque transmission during non-stop heavy digging and long-distance site reloion for fleets of pre-owned heavy excavators.

3. Two-Stage Independent Pre-Delivery Quality Checks Eliminate Costly On-Site Breakdowns

   Every finished assembly undergoes two separate closed-loop inspection workflows before leaving the factory. Full-range dimension calibration verifies all matching tolerances of gear surfaces and inner splines. Simulated open-pit heavy torque aging tests replie extreme harsh working environments to validate long-term transmission stability. All defective semi-finished products are filtered out internally, saving repair shops and mine operators from financial losses caused by unplanned work stoppages.

4. High Cost-Performance OEM-Grade Repair Alternative for Heavy Equipment Operators

   Genuine Doosan original planetary spare parts carry steep procurement costs and inconsistent supply cycles for the discontinued DH300-7 model. Our aftermarket assembly delivers load-bearing capacity and service lifespan equivalent to OEM parts at factory-direct wholesale prices, effectively cutting annual maintenance expenditure for enterprises managing multiple DH300-7 excavators.

5. Versatile Global Logistics Solutions for International Construction Machinery Distributors

   All in-stock items can be shipped within 3 working days once payment is confirmed. Express air freight ers to urgent emergency breakdown orders from remote mountain mining zones. Consolidated bulk sea cargo and full-container FCL shipping provide budget-friendly bulk purchase plans for dealers serving Africa, Southeast Asia, the Middle East and Latin America.

Our workshop specializes in manufacturing planetary transmission spare parts for Korean excavator brands Doosan and Hyundai for over 12 years, with travel gearbox planetary carrier assemblies as our flagship product line. We own a complete closed-loop production chain: alloy steel die forging, 5-axis precision gear machining, constant-temperature heat treatment and finished-product heavy-load simulation testing. Custom heavy-torque test benches replie harsh mine working conditions to continuously upgrade product shock resistance and extend service life. Our planetary transmission spare parts are exported to over 45 countries globally, fostering long-term stable strategic partnerships with heavy machinery spare parts wholesalers worldwide.