KOMATSU PC200-7 PC200-8 Front Idler 20Y-30-00321 Detailed Information

Basic Information

• Primary OEM Part Number: 20Y-30-00321 (also written as 20Y3000321)
• Interchangeable Part Numbers: 20Y-30-00320, 20Y-30-00322, 20Y-30-00030, 20Y-30-08060, KM3299 (Berco)
• Alternative Names: Track Idler Assembly, Front Guide Wheel, Idler Wheel Group
• Category: Excavator Undercarriage Parts - Track Guidance System
• Original Manufacturer: KOMATSU

Compatible Models

This front idler fits the following KOMATSU construction equipment models:

• PC200 Series: PC200-7, PC200LC-7, PC200NLC-7, PC200-8, PC200LC-8, PC200LL, PC200SC
• PC160/PC180/PC190 Series: PC160LC-7, PC160LC-8, PC180LC-7, PC180NLC-7, PC190LC-8, PC190NLC-8
• PC210/PC220 Series: PC210-7, PC210LC-7, PC210NLC-7, PC220-7, PC220LC-7, PC220-8
• PC228/PC230 Series: PC228US-3, PC228USLC-3, PC230-7
• Other Equipment: BR300S-1/2, BR350JG-1, BR380JG, BR480RG-1, BP500, PC110R-1

Technical Specifications

Parameter	Value
Complete Assembly Weight	Approximately 100-112 kg (220-247 lbs)
Roller Body Material	Forged 50Mn / SCMn3A high-strength alloy steel
Surface Treatment	Induction-hardened tread surface
Surface Hardness	HRC 50-57 with 4-10mm deep hardened layer
Shaft Material	42CrMo alloy steel
Shaft Surface Roughness	Ra 0.2-0.4 (precision CNC polished)
Bushing Type	Bi-metal copper bushing (0.6mm thick copper layer)
Seal System	Double floating oil seal with 2% molybdenum content
Lubrication	Factory pre-lubricated with high-temperature lithium grease
Design Life	4000-5000 operating hours under normal conditions
Quantity per Machine	2 units (1 per track)

NPtR
Function: Guides the track chain, maintains proper alignment, absorbs impact loads during travel and turning, and works in conjunction with the track recoil spring to provide continuous tension adjustment.

Market Price & Availability

• Chinese Aftermarket: $180 - $250 per unit (6 months to 1 year warranty)
• European/American Aftermarket: $350 - $500 per unit (1-2 year warranty)
• Genuine KOMATSU: $800 - $1,200 per unit
• Major Aftermarket Brands: Berco, ITR, Blumaq, Costex Tractor Parts, A&S Machinery
• Lead Time: 1-3 days for shipping from Chinese suppliers, 7-15 days for international delivery
• Note: Sold individually. It is highly recommended to replace both front idlers at the same time to ensure even track wear and machine balance.

Related Parts

• 20Y-30-12110: Matching track recoil spring assembly
• 20Y-30-32110: Idler yoke (bracket)
• 20Y-30-13130: Idler shaft pin
• 07177-10050: Idler seal and bushing repair kit
• 20Y-30-11340: Mounting bolt kit
• 20Y-30-00140: Lower track roller (single flange)

Installation & Maintenance Precautions

1. Critical Safety Warning: This front idler weighs over 100kg. Always use proper lifting equipment (chain hoist or forklift) during removal and installation. Never attempt to lift it manually.
2. Pressure Release: Before any work on the track system, slowly loosen the grease fitting on the track adjuster cylinder to release all internal pressure until the track is completely slack.
3. Pre-Installation Inspection: Thoroughly inspect the idler yoke and track frame for cracks, deformation, or excessive wear. Replace any damaged components before installing the new idler.
4. Torque Specification: Tighten the mounting bolts to 120-140 N·m in a crisscross pattern to ensure even pressure distribution and prevent loosening.
5. Alignment Check: After installation, verify that the idler is perfectly aligned with the track chain and drive sprocket. Misalignment will cause accelerated wear to all undercarriage components.
6. Regular Inspection: Inspect the idler every 250 operating hours for:
   • Tread wear (replace if wear exceeds 15mm)
   • Cracks or deformation in the body
   • Oil leakage from the seals
   • Abnormal noise or excessive play
7. Debris Management: Clean accumulated mud, rocks, and debris from around the idler and track frame regularly to prevent track jamming and seal damage.