Komatsu 20y3008050 81E52003 81E520031BG 2073000031 20730K1200 PC360-7 Track Carrier Roller Assy / Track Upper Roller Assembly / Original Manufacturer CQC TRACK Supplies Directly

Komatsu 20Y-30-08050 / 81E-52-0031 / 81E-52-0031BG / 207-30-00031 / 207-30-K1200 PC360-7 Track Carrier Roller Assembly – Track Upper Roller Assembly / Original Manufacturer CQC TRACK Supplies Directly

Author: Jack – Technical Overseas Sales, Heli Undercarriage Parts
Contributing Team: Heli Undercarriage Parts Global Sales & Customization Team

1. Introduction: The Essential Role of Carrier Rollers in Heavy-Duty Undercarriage Systems

The carrier roller, also known as the top roller or upper roller, is a deceptively critical component in the undercarriage system of any crawler excavator. While track rollers bear the full operating weight of the machine against the ground, carrier rollers perform an equally indispensable function: they support the upper run of the track chain as it returns from the front idler to the drive sprocket. Positioned atop the track frame, these rollers maintain proper track sag, guide the track‘s return path, and minimize lateral oscillation and vibration during travel.

When carrier rollers fail—through bearing seizure, seal breach, or flange wear—the upper track chain sags, contacts the track frame, and accelerates wear on both the chain and the undercarriage structure. The result is increased friction, reduced travel efficiency, premature track link wear, and ultimately, costly downtime for repair or replacement.

For the Komatsu PC360-7, a 36-ton class hydraulic excavator widely deployed in mining, quarrying, heavy construction, and earthmoving projects worldwide, the demand for reliable, OEM-quality carrier roller assemblies remains consistently strong. The PC360-7 represents a generation of Komatsu‘s mid-to-large excavator line that continues to operate in large numbers across surface mines, infrastructure projects, and demolition sites—creating sustained aftermarket demand for replacement undercarriage components.

The carrier roller assemblies referenced by part numbers 20Y-30-08050, 81E-52-0031, 81E-52-0031BG, 207-30-00031, and 207-30-K1200 are direct OEM-equivalent replacements designed specifically for the Komatsu PC360-7 and its compatible variants. Manufactured by CQC TRACK (HELI MACHINERY MANUFACTURING CO., LTD.) , a top-tier China-based source factory specializing in heavy-duty crawler excavator undercarriage parts, these assemblies deliver original-equipment quality at competitive factory-direct pricing, serving mining and construction customers across South Africa, South America, North America, Europe, Russia, South Korea, and beyond.

As the author of this technical overview, I am Jack, responsible for technical overseas sales at Heli Undercarriage Parts. Alongside my colleagues and the broader Heli global sales team under the strategic leadership of our major shareholder, we provide comprehensive undercarriage solutions, aftermarket supply, and OEM customization to customers worldwide. In this article, I will present a complete technical and commercial analysis of the Komatsu PC360-7 carrier roller assemblies, including their specifications, manufacturing excellence, global application contexts, and how our team delivers tailored supply-chain support across diverse international markets.

2. The Komatsu PC360-7 Excavator: A Mid-Size Mining Workhorse

2.1 Machine Overview and Global Significance

The Komatsu PC360-7 is a 36-ton class hydraulic excavator that has earned a reputation for reliability, fuel efficiency, and productivity in demanding environments. Part of Komatsu‘s Dash-7 series, the PC360-7 features the Komatsu SAA6D114E engine, advanced hydraulic systems, and a reinforced undercarriage designed for extended service life in rock and heavy digging applications.

Key specifications of the PC360-7 include:

The PC360-7 is widely utilized in mining, quarrying, heavy construction, and earthmoving projects globally. The PC360-7 uses two carrier rollers on each side of the undercarriage to manage the upper track run‘s movement during sharp turns and heavy digging cycles.

2.2 Undercarriage Configuration and Carrier Roller Function

The PC360-7 employs a sealed and lubricated track (SALT) system with press-fit pin and bushing joints. The carrier rollers (upper rollers) are positioned on the top of the track frame, typically two per side for machines in this weight class.

The core functions of the carrier roller assembly include:

• Supporting the upper track chain: The carrier roller supports the return run of the track chain as it travels from the front idler back to the drive sprocket, preventing sagging and frame contact.
• Maintaining proper track tension: By supporting the upper chain, carrier rollers help maintain optimal track tension, which is critical for efficient power transfer and reduced wear on sprockets and links.
• Reducing friction and vibration: The rotating roller minimizes friction between the track chain and the undercarriage frame, reducing energy loss and operator fatigue from vibration.
• Guiding the track return path: The roller‘s flanges guide the track chain laterally, preventing derailment during turning operations.

3. Technical Deep Dive – Komatsu PC360-7 Carrier Roller Assemblies

3.1 Part Number Identification and Cross-Reference

The carrier roller assemblies for the Komatsu PC360-7 are identified by multiple OEM and aftermarket part numbers. Understanding these numbers and their relationships is essential for accurate procurement and inventory management.

Important note: The cross-referenced part numbers 207-30-00031 and 207-30-K1200 are also used across a broad range of Komatsu PC series excavators, including  PC300-5, PC300-6, PC310-5, PC350-6, PC400-5, PC400-6, PC410-5, and PC450-6 models. This cross-model compatibility is valuable for fleet operators managing multiple machine models, as it allows inventory consolidation and simplified procurement.

The part number 20Y-30-08050 is explicitly cross-referenced with applications for Komatsu excavators including . The PC360-7 specifically uses two carrier rollers to manage the upper track‘s movement during sharp turns.

3.2 Physical Specifications

Based on OEM and aftermarket technical data, the Komatsu PC360-7 carrier roller assembly is manufactured to the following specifications:

3.3 Material and Manufacturing Standards

High-quality aftermarket carrier roller assemblies for the Komatsu PC360-7 are manufactured to meet or exceed OEM specifications:

Roller Shell Material:

• High-grade forged medium-carbon alloy steel (e.g., 50Mn, 55Mn, 60Si2Mn), chosen for its exceptional combination of strength, toughness, and hardenability
• Forging ensures a continuous grain flow that follows the contour of the part, significantly enhancing fatigue resistance compared to cast alternatives
• Critical for withstanding repeated high-impact loads from the track chain

Bearing Components:

• Double-row tapered roller bearings for heavy-duty configurations
• Precision-ground bearing surfaces for smooth rotation and reduced friction

Sealing System:

• Multi-layered seal system combining radial seals, O-rings, and dust lips
• Labyrinth seal or float seal configuration providing robust barrier against contamination (abrasive sand, mud, dust)
• Retention of high-performance grease, significantly extending service life and re-lubrication intervals
• Some variants feature double-cone sealing and lubrication-for-life design, ensuring long service life and perfect performance under any working condition

Heat Treatment:

• Body hardening: Through-hardened to a core hardness typically ranging from 50–55 HRC, providing necessary structural integrity to resist deformation under extreme loads
• Flange hardening: Critical flange surfaces receive induction hardening, creating an ultra-hard, wear-resistant layer (58–62 HRC) on flange edges, dramatically extending service life against abrasive wear
• Roller tread undergoes induction hardening or case carburizing processes, creating a deep, wear-resistant surface layer (typically 55–60 HRC) while maintaining a ductile, shock-absorbing core to prevent brittle fracture

3.4 Quality Assurance

Premium aftermarket suppliers subject their carrier roller assemblies to rigorous quality control:

• Spectrographic material analysis – Verification of alloy composition against OEM benchmarks
• Hardness profiling – Rockwell hardness testing at multiple points (surface, flange, core)
• Dimensional inspection – CNC coordinate measuring machine (CMM) verification of roller diameter, flange width, and mounting dimensions
• Magnetic particle inspection (MPI) – Detection of surface cracks on critical components
• Seal integrity testing – Verification of contamination exclusion and lubricant retention
• Rotation smoothness testing – Validation of bearing function under load simulation
• Fatigue simulation – Cyclic loading tests to validate structural durability

3.5 Compatibility Verification

The carrier roller assemblies referenced in this article are direct-fit replacements for the following Komatsu excavator models:

• PC360-7 (primary application)
• PC200-7, PC210-7, PC220LC-7, PC240LC-7 (20Y-30-08050)
• PC160LC-7, PC180LC-7 (20Y-30-08050)
• PC250-6, PC300-5, PC300-6, PC310-5, PC350-6, PC400-5, PC400-6, PC410-5, PC450-6 (207-30-00031 cross-reference)

Fleet operators should confirm compatibility by cross-referencing the existing assembly’s specifications—including roller diameter, flange width, mounting bolt pattern, and overall length—against the replacement part‘s dimensions. Our sales team at Heli Undercarriage Parts provides technical verification support for all orders to ensure perfect fitment.

4. CQC TRACK – Your Original Manufacturer (Source Factory) for Undercarriage Components

4.1 Company Overview

HELI MACHINERY MANUFACTURING CO., LTD. , operating under the industrial brand CQC TRACK, has established itself as one of the top three undercarriage component manufacturers in Quanzhou, China—a key global supply cluster for earthmoving equipment undercarriage parts.

With over 20 years of specialized manufacturing experience, CQC TRACK has built a reputation for excellence in the design and production of heavy-duty crawler excavator undercarriage components. The company operates as a vertically integrated manufacturer, controlling every stage of production from raw material sourcing to final assembly and quality testing.

Key corporate credentials include:

• ISO 9001:2015 certified facility with CQC product certification
• Over 20 years of specialized manufacturing experience
• Vertically integrated operations—raw material to finished assembly
• Specialization in heavy-duty crawler excavator undercarriage parts
• OEM and ODM manufacturing services for customers worldwide

4.2 Manufacturing Capabilities

CQC TRACK leverages advanced manufacturing technologies to produce undercarriage components that meet or exceed OEM specifications:

• Forging lines for roller shells and other chassis components (superior to cast alternatives for fatigue resistance)
• CNC machining centers for precision turning, grinding, and boring of bearing surfaces and mounting interfaces
• Induction hardening equipment for surface wear treatment of roller treads and flanges
• Automated heat treatment lines for consistent material properties across production batches
• Comprehensive quality testing laboratory including chemical spectroscopy, hardness testing, dimensional inspection, and seal integrity validation
• Precision processing technology and specialized heat treatment techniques to achieve best wear resistance and maximum extent loading capacity

4.3 Product Portfolio – The “Four Wheels and One Track”

CQC TRACK‘s core product line encompasses the complete range of undercarriage components for excavators from 1 to 100 tons:

• Carrier rollers (upper rollers / top rollers) – Including Komatsu 20Y-30-08050, 81E-52-0031, 207-30-00031, and 207-30-K1200 assemblies
• Track rollers (bottom rollers / lower rollers) – Load-bearing rollers for track guidance and weight distribution
• Front idlers – For track tensioning and guidance
• Sprockets (drive rims) – With precision-machined teeth for final drive engagement
• Track chains (track link assemblies) – Sealed and lubricated configurations
• Track shoes – Various widths and patterns (single-grouser, double-grouser, flat)
• Complete undercarriage kits – Pre-assembled solutions for major brands including Komatsu, Caterpillar, Hitachi, Volvo, LiuGong, SANY, and XCMG

This product breadth allows customers to source entire undercarriage replacement sets from a single supplier, simplifying procurement logistics and ensuring component compatibility across the track system.

4.4 OEM Quality, Source Factory Pricing

As a source factory (original manufacturer), CQC TRACK provides customers with distinct advantages over trading companies and third-party intermediaries:

Our overseas business is conducted through direct communication with our sales team—no third-party intermediaries—ensuring full transparency in pricing, lead times, quality control, and after-sales support.

4.5 Custom Undercarriage Solutions

CQC TRACK‘s engineering team specializes in custom undercarriage solutions, recognizing that off-the-shelf parts may not always meet the unique demands of specialized projects—such as operating in extreme climates, handling oversized loads, or integrating with retrofitted machinery.

Customization options include:

5. Global Market Coverage – Serving Mining and Construction Customers Across Continents

The Heli Undercarriage Parts global sales team—including myself (Jack) in technical overseas sales, and our broader team under the strategic leadership of our major shareholder—manages a worldwide network of customers in the mining and construction sectors. Below, I provide an overview of our service capabilities across key geographic markets.

5.1 South Africa – A Strategic Mining Hub

South Africa remains one of the world‘s most significant mining regions, with large installed fleets of Komatsu excavators operating in platinum, gold, diamond, coal, and iron ore mines. The South African mining equipment aftermarket continues to generate sustained demand for replacement undercarriage parts, particularly as new equipment prices rise and contractors face margin pressure.

For customers in South Africa, the Heli team offers:

• Direct factory shipping to Durban, Cape Town, and Johannesburg ports
• Technical support for Komatsu PC360-7 and other excavator models
• Bulk order capability for fleet operators with multiple machines
• Custom packaging to withstand long-distance ocean freight

5.2 South America – Growing Infrastructure and Mining Demand

South America‘s construction equipment market is experiencing robust growth, driven by aggressive infrastructure development agendas across the continent. Brazil, Chile, Peru, and Argentina have particularly high demand for heavy mining and construction machinery, creating substantial aftermarket opportunities.

The Heli team serves South American customers through:

• Warehousing partnerships in São Paulo (Brazil) and Buenos Aires (Argentina)
• Spanish and Portuguese technical documentation available upon request
• Support for mining operations in the Andean copper belt and Brazilian iron ore regions
• Aftermarket parts for Komatsu PC360-7 and other PC series excavators operating in the region

5.3 North America – Quality-Driven Aftermarket

The North American market—including the United States and Canada—demands the highest standards of quality, reliability, and compliance. Mining operations in the Canadian oil sands, U.S. coal fields, and aggregate quarries across both countries require undercarriage components that deliver extended service life in extreme conditions.

For North American customers, Heli Undercarriage Parts provides:

• Bonded stock availability from warehouse locations
• ISO-certified quality documentation for procurement compliance
• Technical datasheets in English with full specification details
• Sample testing program – 10-piece trial shipments for on-site validation

5.4 Europe – Rigorous Standards, Competitive Solutions

The European mining and construction equipment market is characterized by demanding technical standards, environmental regulations, and cost-conscious fleet operators. European customers require undercarriage parts that meet or exceed OEM specifications while offering competitive pricing.

The Heli team serves European customers through:

• CE-marked components where applicable
• Fast shipping to Rotterdam, Hamburg, and Antwerp ports
• Technical support for Komatsu PC360-7 and other excavator models
• Compliance documentation for EU market requirements
• Aftermarket supply for the substantial installed base of Komatsu equipment across Europe

5.5 Russia and CIS Countries – Resilient Market Demand

The Russian undercarriage component market continues to experience steady demand, driven by ongoing construction, mining, and infrastructure activity. The large installed base of Komatsu equipment in the region creates ongoing aftermarket requirements.

For Russian and CIS customers, Heli provides:

• Direct shipping to Vladivostok, St. Petersburg, and Novorossiysk ports
• Russian-language technical documentation available upon request
• Customs clearance support for efficient border processing
• Aftermarket parts for Komatsu PC360-7 and other PC series excavator models

5.6 South Korea – Precision Manufacturing Demands

South Korea represents a sophisticated market with high expectations for product quality, precision, and delivery reliability. Korean customers—including parts distributors and equipment rental companies—demand components that match the tight tolerances of Korean-manufactured equipment.

The Heli team serves South Korean customers through:

• Precision machining to tight dimensional tolerances
• Fast shipping to Busan and Incheon ports
• Sample approval process prior to bulk production
• Technical consultation for model-specific fitment verification

6. The Heli Undercarriage Parts Global Sales Team

Behind every reliable undercarriage component is a dedicated team of sales professionals and technical experts. Heli Undercarriage Parts is not just a supplier—it is a full-service partner offering customized global sales solutions for undercarriage components.

6.1 Author: Jack – Technical Overseas Sales

I am Jack, responsible for technical overseas sales at Heli Undercarriage Parts. My role bridges the gap between field requirements and engineering reality. Whether you need wear life predictions for a specific mining application, urgent air freight to a remote mine site, or technical documentation for procurement compliance, I coordinate the response from initial inquiry through post-delivery support.

6.2 The Global Sales Team

The Heli global sales team, under strategic leadership, manages worldwide customer relationships, including:

• Technical consultation – Model-specific fitment verification and application recommendations
• Logistics coordination – Warehousing in key markets and 24/7 supply chain management
• After-sales support – Warranty programs, spare parts availability, and technical guidance
• Strategic partnerships – Long-term agreements with mining houses and parts distributors

Our overseas business is conducted through direct communication with our sales team—no third-party intermediaries—ensuring full transparency in pricing, lead times, quality control, and after-sales support.

The company‘s international sales team can try all efforts to offer the best service and the top first-class products to clients to help them to get more market share globally.

7. Aftermarket Supply and OEM Customization Solutions

7.1 Global Undercarriage Market Context

The global undercarriage components market continues to experience substantial growth, driven by expanding construction, mining, and infrastructure activities worldwide. Key factors propelling market expansion include:

• Technological advancements in material engineering, enhanced durability, and wear resistance
• Increasing demand for efficient and reliable undercarriage systems in mining operations
• Rising replacement demand due to the aging fleet of heavy machinery
• Growing infrastructure development in emerging economies, particularly in the Asia-Pacific region

7.2 Aftermarket Parts Supply

As a source factory, CQC TRACK is positioned to capture this growing aftermarket demand by offering:

• Direct factory pricing – 30–50% below dealer pricing on comparable quality
• Short lead times – 15–25 days for standard production runs
• Low minimum order quantities – 200 pieces for initial sample trials
• Mixed container shipments – Combine carrier rollers, track rollers, idlers, and sprockets in one order
• Warranty program – 12–24 months depending on configuration

7.3 OEM Customization Services

For customers requiring parts under their own branding or with specific engineering modifications, CQC TRACK offers comprehensive ODM (Original Design Manufacturing) services:

7.4 Complete Undercarriage Solutions

In addition to the carrier roller assemblies referenced in this article, CQC TRACK manufactures a complete range of undercarriage components for Komatsu PC series excavators:

• Track chains – Sealed and lubricated (SALT) or dry configurations
• Track rollers (bottom rollers) – Load-bearing rollers for track guidance
• Carrier rollers (upper rollers / top rollers) – Supporting the upper track run
• Sprockets (drive rims) – With precision-machined teeth for final drive engagement
• Track shoes – Various widths and patterns
• Front idlers – For track tensioning and guidance
• Complete track groups – Fully assembled ready-to-install solutions

8. Ordering Information and Technical Support

8.1 Product Specifications – Komatsu PC360-7 Carrier Roller Assemblies

8.2 Contact Information – Heli Undercarriage Parts Global Sales Team

I invite customers and distributors to contact our team directly for pricing, technical documentation, and sample orders:

• Jack (Technical Overseas Sales – Author of this article): j_sales@cqctrack.com
• Office address: Heli Machinery Manufacturing Co., Ltd. (CQC TRACK), Quanzhou Economic Development Zone, Fujian, China (362000)

9. Conclusion – Why Choose CQC TRACK for Your Komatsu PC360-7 Carrier Roller Needs

The Komatsu PC360-7 excavator remains one of the most reliable mid-size hydraulic excavators ever produced, with thousands of units still operating in mines, quarries, and major construction sites worldwide. Keeping these machines productive requires reliable, high-quality undercarriage components that match OEM specifications and deliver extended service life in demanding environments.

The carrier roller assemblies referenced by part numbers 20Y-30-08050, 81E-52-0031, 81E-52-0031BG, 207-30-00031, and 207-30-K1200—manufactured by CQC TRACK (HELI MACHINERY MANUFACTURING CO., LTD.) —represent the optimal balance of OEM-equivalent quality, competitive factory-direct pricing, and reliable supply.

As the global sales team at Heli Undercarriage Parts, we are committed to providing:

• Technical expertise – Backed by over 20 years of specialized undercarriage manufacturing experience
• Global reach – Serving mining and construction customers across South Africa, South America, North America, Europe, Russia, South Korea, and beyond
• Customer focus – Direct communication with our sales team, no third-party intermediaries
• Supply reliability – Source factory production with full quality control and ISO certification

Whether you are a mining fleet operator seeking to reduce parts costs, a distributor building inventory for the aftermarket, or an OEM requiring custom undercarriage components, the Heli team is ready to support your requirements.

Contact us today to discuss your Komatsu PC360-7 carrier roller needs.

Author: Jack – Technical Overseas Sales, Heli Undercarriage Parts. Technical data based on manufacturer specifications, industry standards, and cross-referenced parts catalogs. For reprint permission or technical inquiries, contact the author directly.