PC300-5 PC300-6 6222-31-1100 6221-31-1100 6D108 Komatsu 6D108 Forged Steel Engine Crankshaft Compatible with Komatsu

1. Product Overview & Wholesale Price Range

The Komatsu 6D108 / S6D108 Forged Steel Engine Crankshaft (OEM Part # 6222-31-1100 / 6221-31-1100 / 6222-31-1200) is a heavy-duty 6-cylinder forged alloy steel crankshaft with induction-hardened journal surfaces designed for 30-ton excavators and loaders operating under extreme quarrying and heavy earthmoving conditions.

• Factory Wholesale Price: $680 – $1,350 USD (Direct manufacturer pricing — Save up to 50% vs regional dealer markups)
• Material Specifications: High-purity 42CrMo forged alloy steel + Nitrided journal surface hardening (HRC 55-60)
• Dynamic Balance Test: 100% precision dynamic balanced with 0.01mm journal runout tolerance
• MOQ & Bulk Discount: 1 Unit (Tiered wholesale discounts available for engine rebuild shop container orders)
• Lead Time: 1–3 business days (Large factory stock ready for immediate worldwide dispatch)
• Warranty: 12 Months full replacement warranty against shaft breakage or material fatigue

2. Application Worksite Checklist (施工场景清单)

Engineered to withstand extreme peak firing pressure and torsional fatigue in harsh mining environments:

• Heavy Open-Pit Quarrying & Rock Mining: High fatigue strength resists continuous torque spikes during heavy rock loading with Komatsu PC300-6 excavators.
• Deep Mass Foundation Excavation: Precision balanced journals ensure smooth engine rotation under 2,200 RPM continuous load.
• Highway Infrastructure & Earthmoving: Nitrided journal coating protects against bearing friction wear during long continuous operating shifts.
• Heavy Wheel Loader Operations: Reinforced flywheel flange and snout splines handle high acceleration loads on Komatsu WA380-3 loaders.

3. Engine Crankshaft Troubleshooting & Diagnostic Guide (曲轴常见故障排查)

If your Komatsu 6D108 / S6D108 engine is undergoing overhaul or exhibiting mechanical damage, consult the guide below:

• Fault 1: Crankshaft Fatigue Fracture or Snapping Under High Load (曲轴疲劳断裂/受力拉断)
  Root Cause: Severe torsional vibration, main bearing bore misalignment, or casting micro-voids in low-quality cast crankshafts.
  Solution: Replace with our 42CrMo forged steel 6D108 crankshaft (OEM 6222-31-1100) with 100% ultrasonic crack testing.
• Fault 2: Connecting Rod / Main Journal Scoring, Deep Grooves & Bearing Seizure (轴颈拉伤/烧瓦抱轴)
  Root Cause: Contaminated engine oil, insufficient lubrication pressure, or excessive oil operating temperatures.
  Solution: Regrind journals to undersize or install a factory-new nitrided 6D108 forged crankshaft with new bearings.
• Fault 3: Crankshaft Bending Runout & Severe Engine Vibration (曲轴弯曲变形/发动机剧烈抖动)
  Root Cause: Over-speeding, flywheel impact shock, or unbalanced pistons and connecting rods.
  Solution: Replace damaged crankshaft with our 100% dynamic balanced 6D108 crankshaft (runout ≤ 0.01mm).
• Fault 4: Rear Oil Seal Journal Wear & Crankshaft End Oil Leakage (后油封位磨损渗油)
  Root Cause: Abrasive dust ingress wearing deep grooves into the rear crankshaft oil seal journal surface.
  Solution: Install our induction-hardened rear oil seal journal 6D108 crankshaft assembly.

4. Hot Machinery Replacement Parts Recommendation (5大品类热门推荐表)

Explore our factory-direct replacement engine and hydraulic components compatible with major global excavator brands:

5. Frequently Asked Questions & Technical Support (QA 问答专区)

Q1: How do I verify if this 6D108 forged steel crankshaft fits my Komatsu PC300-6 excavator engine?
A: Check your original crankshaft casting or engine tag for OEM numbers 6222-31-1100, 6221-31-1100, or 6D108 / S6D108 stamp. You can also send us photos of your old crankshaft flange for instant fitment verification.

Q2: What is the manufacturing process and journal hardness of this Komatsu 6D108 crankshaft?
A: Our 6D108 crankshafts are forged from 42CrMo high-purity alloy steel with full CNC grinding and nitrided journal surface hardening (HRC 55-60), achieving 3x higher fatigue resistance than cast iron shafts.

Q3: Is this Komatsu 6D108 forged crankshaft dynamic balanced before shipment?
A: Yes, every single 6D108 crankshaft undergoes 100% dynamic balance testing and Magnaflux magnetic particle flaw inspection to ensure zero internal cracks and runout ≤ 0.01mm.