Doosan DH420 Travel Gearbox 1st Planetary Carrier Spider With Sun Gear Assy For Excavator Parts

This integrated first-stage planetary spider and sun gear unit acts as the primary torque reduction core at the input end of DH420’s travel final drive, custom-made for Doosan DH420 large heavy crawler excavators. This heavy-duty model is dominant in large open-pit mines, mountain road excavation, large-scale land reclamation and river dredging projects. It runs under long-duration heavy digging loads, frequent steep slope climbing and repeated rock collision impact, which imposes extreme alternating torque on the 1st planetary set.

Once the carrier spider arms crack, sun gear tooth surfaces peel or internal splines suffer excessive wear, the machine will suffer laggy walking response, obvious left-right track speed difference, constant shrill metal grinding noise and severe overheating of the whole travel motor housing.

Every gear tooth contour, inner spline size and mounting hole position strictly follows original Doosan OEM drawing standards. The assembly is a direct replacement without any on-site cutting, reaming or modifiion, greatly shortening equipment downtime. It perfectly solves the points of high prices and long delivery cycles of genuine Doosan original spare parts, ideal for overseas second-hand excavator fleets operating in Africa, Southeast Asia and Middle East mining regions.

1. 1:1 OEM Exact Matching, Exclusive Fit for Doosan DH420 Travel Final Drive

   
   

   This planetary carrier and sun gear combo is precisely sized to match the internal cavity of DH420 travel reducers, and cannot be installed on other Doosan heavy excavators like DH370 or DX420. Accurate repliion of original spline and gear meshing gaps avoids track deviation, unstable shaking during travel, harsh internal friction noise and premature abrasion of matched transmission parts after installation.

2. One-Piece Thick Forged Structure Extends Service Life Under Severe Mining Working Conditions

   
   

   Low-cost generic aftermarket planetary carriers often crack spider arms or break sun gear teeth under round-the-clock continuous heavy mining loads. Our integral thick die forging craft plus full multi-stage constant-temperature heat treatment greatly improves impact resistance and fatigue resistance. It maintains stable torque transmission during non-stop large-volume excavation and long-distance cross-site reloion for rental and pre-owned heavy excavator fleets.

3. Two Independent Pre-Delivery Quality Inspections Avoid Costly On-Site Construction Stops

   
   

   Each finished assembly undergoes two separate closed-loop inspection procedures before leaving the factory. Full-range dimension calibration verifies all matching tolerances of gear surfaces and inner splines. Simulated large open-pit mine heavy torque aging test replies extreme harsh working loads to verify long-term transmission stability. All defective semi-finished products are eliminated internally, helping repair shops and mine operators reduce economic losses caused by unplanned machine downtime.

4. Cost-Effective OEM-Grade Repair Solution for Large Excavator Fleet Owners & Local Repair Garages

   
   

   Genuine Doosan original planetary spare parts have extremely high purchase costs and unstable supply cycles for DH420, a classic heavy excavator widely circulated overseas. Our aftermarket assembly reaches OEM equivalent load-bearing capacity and service life at factory direct wholesale prices, effectively cutting annual maintenance costs for enterprises managing multiple DH420 heavy machines.

5. Flexible Global Logistics for International Construction Machinery Spare Parts Distributors

   
   

   All in-stock items can be dispatched within 3 working days after payment confirmation. Air freight serves 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 covering Africa, Southeast Asia, Middle East, Central Asia and Latin American markets.

Our workshop has over 12 years of specialized R&D and mass production experience focused on planetary transmission spare parts for Korean brand excavators (Doosan & Hyundai), with travel gearbox planetary carrier assemblies as our core flagship product line. We own a complete closed-loop production chain: alloy steel die forging, 5-axis precision gear processing, constant-temperature professional heat treatment and finished product heavy-load simulation testing. Custom heavy-torque test benches simulate harsh large mine and highway construction environments to continuously optimize product shock resistance and extend service life. Our planetary transmission spare parts are exported to more than 45 countries worldwide, building long-term stable strategic partnerships with heavy machinery spare parts wholesalers globally.

Q1: Can this first-stage planetary carrier assembly fit other Doosan excavator models besides DH420?
A1: Cross-model compatibility is not supported. Different Doosan excavator series adopt final drive assemblies with unique non-interchangeable structural sizes and spline parameters. Please confirm your exact machine model before placing orders.

Q2: What travel gearbox faults can this assembly fix?
A2: It resolves equipment failures caused by cracked carrier spider support arms, severely worn or chipped sun gear teeth, offset wobbling tracks, continuous harsh internal gear friction noise and insufficient travel driving power output.

Q3: Do you offer tiered volume discounts for large wholesale orders?
A3: Yes, graded preferential pricing is available based on order quantity. We can arrange full-container sea transportation to cut total international logistics costs for large-batch procurement.

Q4: What anti-rust and shockproof packaging is used for long-distance ocean shipping?
A4: All metal surfaces are evenly coated with high-viscosity heavy-duty anti-rust grease. The entire assembly is wrapped with multi-layer thick waterproof and shockproof PE film, then sealed and packed in reinforced export plywood crates to prevent scratches, collision deformation and damp corrosion during long overseas sea transit.