Description
Crawler track propulsion on the Komatsu PC20-7 mini excavator demands balanced tractive torque to navigate muddy utility trenches and climb equipment trailers. Tatan Machinery supplies 100% Brand New GM06 complete final drive travel motor assemblies (OEM reference: 20S-60-31120 / 20S-60-31121, backward compatible with 20S-60-31110 / 843000150). Each complete drive integrates a two-speed variable hydraulic axial piston motor with an ultra-compact planetary reduction gearbox, backed by our 12-Month Comprehensive Replacement Warranty.
Source Verification: First-Party Physical Stockholding
We are a specialized stocking supplier of excavator hydraulic components. We do not dropship unverified goods. All hydraulic pumps, control valves, and final drives supplied on our site are 100% Brand New (our diesel engine assemblies are remanufactured to OEM tolerances).
| Supplying Entity: | Tatan Machinery (Excavator Component Exporter) |
| Component Classification: | Final Drive Travel Motor / Undercarriage Parts |
| Internal Drive Model: | GM06 / TM06 Two-Speed Piston Motor + Planetary Reduction Box |
| OEM Master Assembly Code: | 20S-60-31120 / 20S-60-31121 (Alt: 20S-60-31110, 843000150) |
| Manufacturing Standard: | 100% Factory Brand New (Unused, Pre-Assembled Drop-in Unit) |
| Target Machine Brand: | Komatsu Excavator Parts Collection |
📦 Physical Inventory & Staging Verification
On-shelf stock ready for crating, palletized final drive storage, and serial tag inspection:
Physical inventory verified — no broker middleman. Live photos of serial number tags provided upon inquiry.
Track Drive Mechanical & Hydraulic Specifications
| Engineering Property | Design Metric |
|---|---|
| Drive Motor Core Type | GM06 / TM06 Two-Speed Variable Displacement Axial Piston Motor |
| Planetary Gearbox Staging | Two-Stage Planetary Gear Reduction with Carburized Steel Pinions |
| Maximum Working Pressure | 20.6 MPa (210 bar / 2,987 PSI) Main Circuit Threshold |
| Dual Travel Velocity | Low Speed (2.0 km/h High Tractive Force) / High Speed (3.5 km/h Fast Tracking) |
| Mechanical Parking Brake | Hydraulically Released, Spring-Applied Wet Friction Multi-Disc Brake |
| Gearbox Lubricant Volume | Approx. 0.55 Liters SAE 80W-90 Extreme-Pressure Gear Oil |
| Dry Assembly Weight | Approx. 38.5 kg (84.8 lbs) Complete Track Drive |
| Machine Fitment Range | Komatsu PC20-7, PC20R-7, PC25-1 (2.6-Ton Class Mini Excavators) |
Field Diagnostics: Root Causes of PC20-7 Track Drive Failure
Operating a 2.6-ton excavator in sticky mud, backfilling basements, and counter-rotating tracks places extreme torsional stress on final drives. When tracking fails, field overhauls usually result in repeated breakdowns:
- Track Tension Over-Tightening & Main Bearing Fatigue: Machine operators frequently over-grease track adjusters. Excessive track chain tension puts enormous radial side-loading on the final drive hub, crushing the heavy tapered roller bearings and tilting the planetary carrier.
- Mechanical Floating Seal Wire Ingress: Fine demolition wire or roots packing into the sprocket recess chew through the rubber O-rings supporting the duo-cone floating seals. Once the small oil volume (~0.55L) drains, planet gears weld together in less than 100 meters of tracking.
- Two-Speed Shift Spool Sticking: Contaminated hydraulic fluid jamming the internal shift piston on the GM06 motor head. The machine refuses to downshift into high-torque low gear, causing the excavator to stall when attempting to climb onto transport trailers.
- Motor Barrel Slippage & Single-Track Pulling: Scoring across the motor valve plate dumping high-pressure fluid into the case-drain line. The excavator continuously veers toward the weak track side when travel levers are pushed full forward.
Factory Dyno Testing & 12-Month Component Warranty
To guarantee immediate reliability on your worksite, every 20S-60-31120 final drive is tested on our automated hydraulic test bench under full working parameters before export approval:
- Two-Speed Shift Hydraulic Transition Verification: Verifying smooth, instant swashplate shift between high-speed tracking and low-speed climbing under 20.6 MPa circuit pressure.
- Counterbalance Valve Anti-Runaway Hold Test: Testing the dynamic brake valve spool to ensure the track will not over-speed or free-wheel when tracking downhill.
- Duo-Cone Floating Seal Air Decay Integrity: 1.5 bar pneumatic air hold test on the planetary hub cavity to certify 100% seal integrity before gear oil filling.
- Mounting Pilot & Sprocket PCD Accuracy Check: CMM coordinate measurement of sprocket bolt hole centers and track frame pilot rings to eliminate installation binding.
📹 Workshop Final Drive Dyno Testing Live Clip
Watch our technician inspect track motor shift pressure, hub rotation, and port caps:
✓ Live unit filmed on hydraulic test stand at Tatan Machinery facility
Export Packing & Moisture Defense
Track drive planetary assemblies require robust packaging to resist ocean humidity and rough cargo transshipment:
- Threaded Metal Port Plugs: Main travel ports, case drain line, and 2-speed shift signal ports sealed with heavy-duty metal blanking caps.
- Marine Anti-Rust Wax: External bare hub surfaces, sprocket mounting faces, and bolt threads coated with heavy marine anti-rust wax.
- Solid Structural Base Mounting: The drive unit is bolted down upright to high-density solid wood base skids to prevent tipping during transit.
- ISPM 15 Fumigation-Free Solid Plywood Box: Fully enclosed export crate banded with multiple high-tensile galvanized steel straps.
Sealed ports, protective anti-corrosion wax, and reinforced wooden crating
Worldwide Express & Freight Transit
Prompt logistics dispatch adapted for urgent machine-down emergencies and trade stock:
- Air Express (3–7 Days Door-to-Door): Handled via DHL Express, FedEx, or air cargo for rapid jobsite recovery.
- Sea Freight Consolidation: Economical LCL shipping for distributors stocking multiple units.
- Tariff-Ready Paperwork: Commercial invoice detailing official HS Code (8483.40 / 8412.29), packing lists, and Certificate of Origin (COO) upon request.
Daily overseas air express dispatches and consolidated container freight
Field Commissioning Rules: Protect Your New Final Drive
Planetary gears and travel motors operate under extreme torque. You MUST perform these steps during assembly:
- MANDATORY: Fill Planetary Gearbox Oil Before Tracking: Final drives are shipped dry or with minimal testing lubricant. Rotate the hub until one plug is at 12 o’clock (fill) and one is at 3 o’clock (level). Fill with clean SAE 80W-90 gear oil (~0.55L) until oil weeps from the level plug! Tracking with dry gears will destroy the planetary train in 50 meters!
- Pre-Fill Motor Casing with Clean Hydraulic Oil: Disconnect the case-drain line and pour clean hydraulic oil into the motor housing before connecting the hose. Dry-starting the hydraulic motor will instantly burn out the slipper shoes.
- Sprocket Bolt Torque & Threadlocker: Clean the track drive sprocket mating face. Apply Loctite 271 high-strength threadlocker to all sprocket bolts and torque strictly in a criss-cross pattern.
- Verify Case-Drain Line Pressure: Ensure the case-drain line back to the swivel joint and hydraulic tank is completely unobstructed. Any backpressure over 0.3 MPa will blow out the motor main shaft seal into the planetary gearbox!
- Low-Speed Track Air Bleeding: Elevate the track using the boom. Run the track in forward and reverse at low idle for 5 minutes without load to purge all trapped air from the hydraulic lines.
Procurement Decision FAQ: What Buyers Ask
Q: Is this 20S-60-31120 drive a complete unit with the gearbox, or only the hydraulic motor?
A: This is a complete, fully assembled drop-in final drive. It includes the complete GM06 hydraulic two-speed axial piston motor, the two-stage planetary reduction gearbox, the mechanical parking brake pack, and the counterbalance motion control valve. It is ready to bolt directly onto your PC20-7 track frame.
Q: Are your final drives brand new or rebuilt? What is your warranty coverage?
A: This final drive assembly is 100% Brand New with zero operating hours, backed by our 12-Month Comprehensive Replacement Warranty. All gears, planetary carriers, bearings, floating seals, and hydraulic motor components are brand new. (Please note: On our site, all hydraulic pumps, valves, and travel motors are 100% Brand New; only diesel engines are remanufactured).
Q: My PC20-7 has part number 20S-60-31121 or 843000150. How do you confirm fitment?
A: 20S-60-31120, 20S-60-31121, 20S-60-31110, and 843000150 are directly interchangeable Komatsu OEM part numbers used across PC20-7, PC20R-7, and PC25-1 production batches. Send your machine’s serial number (PIN) from the cab tag and clear photos of your current travel motor nameplate to Gavin. We verify the exact bolt hole pattern and sprocket diameter in the official Komatsu parts database within 10 minutes.
Q: Can I see live photos and stamped serial numbers of the actual final drive before dispatch?
A: Absolutely yes. Prior to balance payment and dispatch, we send clear photos and live video of the exact unit assigned to your order. You will see the stamped serial tag, sprocket bolt hole circle, sealed steel port plates, and the wooden box packaging process.
Q: What happens if the crate is damaged during sea freight, and what customs documentation is supplied?
A: Every shipment from Tatan Machinery is protected by full commercial marine cargo insurance. The drive is bolted down directly onto internal skids within a fumigation-free solid plywood crate. We supply commercial invoices with accurate HS Codes (8483.40 / 8412.29), detailed packing lists, and Certificates of Origin for smooth customs clearance at your destination port.
🔗 Frequently Purchased Together with Komatsu PC20-7 Final Drive:
- DIESEL ENGINE:
Komatsu PC20-7 3D84N-2H Diesel Engine Assembly (YM129158-77010)
Remanufactured - MAIN VALVE:
Main Control Valve Assembly (709-35-11100) for Komatsu PC20-7
100% Brand New - HYDRAULIC PUMP:
Main Hydraulic Pump Assembly (705-41-01050) for Komatsu PC20-7
100% Brand New - SWING MOTOR:
Hydraulic Swing Motor Assembly for Komatsu PC20-7
100% Brand New - BRAND CATALOG:
View All Komatsu Excavator & Heavy Equipment Parts Collection
Get Wholesale Factory Quote for PC20-7 Final Drive 20S-60-31120
Looking for direct factory pricing, stock availability, or 12-month warranty terms for Komatsu PC20-7 travel drives? Contact senior specialist Gavin now!
💡 Fast Quote: Send your machine serial number or current travel motor photos for an accurate match within 10 minutes!
* Note: Wholesale Reference Price Starts From $300.00. Please contact Gavin for a final customized quote.
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