Track Roller Group-KM3058/4473719/9109493/ for Komatsu-PC650-8/ PC600LC 6/JD550LC/ZX650H excavator undercarriage parts

Product Specifications

The Komatsu PC650-8 track roller assembly (KM3058, 4473719, 9109493)is a critical undercarriage component that supports the weight of the excavator and ensures smooth track movement. Below are key details about this part:

Komatsu PC650-8 Track Roller Assembly Specifications:

• Part Number: Varies depending on the exact model and configuration (e.g., 6771-31-3110 for some variants).

• Function: Supports the track chain and distributes the machine's weight.

• Material: High-strength steel with hardened surfaces for durability.

• Seals & Lubrication: Typically includes heavy-duty seals (often Komatsu K-type seals) and is grease-lubricated.

• Compatibility: Designed specifically for the Komatsu PC650-8 excavator.

Common Issues & Maintenance Tips:

1. Wear & Damage:

   • Inspect rollers regularly for cracks, flat spots, or excessive wear.

   • Replace if seals are leaking grease, as contamination can cause failure.

2. Lubrication:

   • Ensure proper greasing intervals per Komatsu’s service manual.

3. Alignment Issues:

   • Misaligned rollers can cause uneven track wear.

Excavator Track Roller: Comprehensive Guide

1. Definition & Function

• Primary Role: Supports the excavator's weight and guides the track chain along the undercarriage.

• Key Functions:

  • Distributes machine load evenly across tracks

  • Maintains track alignment (prevents lateral slippage)

  • Reduces friction between track links and undercarriage

2. Types of Track Rollers

Type	Design Features	Applications
Single-Flange	One raised edge on outer side	Standard excavators, flat terrain
Double-Flange	Flanges on both sides	Rough terrain, slope operations
Sealed/Lubricated	Grease-filled with dust seals	High-hour machines, abrasive environments
Non-Flanged	Smooth cylindrical surface	Specialized low-speed applications

3. Critical Specifications

• Bore Size: Matches pin diameter (common: 40-100mm)

• Roller Width: Varies by machine class (mini excavator vs. 50-ton+)

• Material:

  • Shell: Hardened alloy steel (HRC 55+)

  • Bushings: Bronze or composite alloys

• Load Rating: Typically 5-30 tons per roller

4. Wear Indicators

• Visual Signs:

  • 3mm flange wear

  • Flat spots >10% of roller circumference

  • Visible cracks or spalling

• Operational Symptoms:

  • Track misalignment

  • Unusual grinding noises

  • Increased track slap/vibration

5. Maintenance Best Practices

• Inspection Frequency:

  • Every 250 operating hours (severe duty)

  • Every 500 hours (normal conditions)

• Lubrication:

  • Grease type: NLGI #2 lithium complex

  • Interval: Per OEM manual (typically 8-50 hours)

• Replacement Protocol:

  • Always replace in matched sets

  • Verify track chain wear compatibility

  • Torque bolts to manufacturer specs

6. OEM vs Aftermarket Considerations

• OEM Advantages:

  • Precise metallurgical specifications

  • Warranty coverage

  • Guaranteed fitment

• Aftermarket Value:

  • Cost savings (30-50% less)

  • Improved designs (e.g., triple-lip seals)

  • Faster availability for older models

7. Failure Analysis

Failure Mode	Root Cause	Preventive Action
Seal leakage	Contaminated grease	Regular undercarriage cleaning
Bushing wear	Improper lubrication	Use high-temp extreme pressure grease
Flange fracture	Track tension too high	Follow OEM tension specs
Axle seizure	Water intrusion	Submerge testing during rebuilds

8. Global Market Overview

• Top Manufacturers:

  • Japan: Komatsu, Hitachi

  • Europe: Berco, Liebherr

  • USA: Caterpillar, ITR

  • Korea: Doosan, Hyundai

• Price Range:

  • Mini excavator: $80-$200/roller

  • 20-ton class: $300-$600/roller

  • Mining excavators: $1,500+/roller

9. Installation Tips

1. Clean mounting surfaces thoroughly

2. Pre-lubricate bushings before assembly

3. Use proper hoisting equipment (rollers weigh 15-150kg)

4. Stage replacements during undercarriage overhauls

10. Emerging Technologies

• Smart Rollers: Embedded sensors for wear monitoring

• Composite Materials: Polymer-coated rollers for wet environments

• Modular Designs: Quick-change cartridge systems

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This technical breakdown covers all critical aspects of track rollers while maintaining clear organization for easy reference. The table-based comparisons and structured sections enable quick comprehension of complex engineering considerations. Would you like additional details on any specific section?