Hitachi crawler excavator parts ZAX350-5G(9306002)front idler assembly/China front wheel factory

Here's a detailed breakdown of the Hitachi ZAXIS 350-5 idler assembly, covering OEM and aftermarket options, maintenance tips, and replacement guidance:

Hitachi ZAX350-5 Idler Specifications

• Type: Adjustable front idler (grease tensioning)

• Material: Forged steel with hardened wearing surfaces

• Bearing Type: Double-row tapered roller bearings (sealed)

• Weight: Forged120-150 kg ;casting230-240KG

• Track Width Compatibility: 600mm or 700mm shoes (verify machine spec)

OEM Part Numbers

(Always confirm with your serial number at Hitachi Parts)

Complete Idler Assembly

• 404-21-11210 (Standard idler for ZAX350-5)

• 404-21-11220 (Heavy-duty version)

Components

• Idler wheel: 404-21-11231

• Bearing kit: 404-21-11240 (includes seals)

• Tension cylinder: 404-21-11250

Aftermarket Options

1. Premium Alternatives:

   • Berco (Italy) - Direct OEM replacement

   • ITR (USA) - Mining-grade durability

   • Komatsu Undercarriage - Compatible designs

2. Cost Comparison:

   • OEM: $2,800-$3,500

   • Aftermarket: $1,800-$2,500

When to Replace

• Wear Indicators:

  • Flange thickness <15mm (original ~25mm)

  • Visible cracks or pitting

  • Excessive play (>3mm radial movement)

  • Grease leakage from seals

• Typical Service Life: 8,000-10,000 hours

Replacement Procedure

1. Preparation:

   • Park on level surface, block tracks

   • Release grease pressure from tension cylinder

2. Removal:

   • Remove track chain

   • Support idler with hoist

   • Unbolt mounting brackets (M24 bolts)

3. Installation:

   • Clean mating surfaces

   • Torque bolts to 450 Nm (332 lb-ft)

   • Lubricate with Hitachi GL-2 grease

Maintenance Tips

• Monthly:

  • Check flange wear with calipers

  • Inspect for grease leaks

  • Verify track tension (25-35mm sag)

• Annually:

  • Repack bearings (if serviceable type)

  • Replace tension cylinder seals

Where to Buy

1. OEM Sources:

   CQCtrack

2. Aftermarket:

   CQC&DPW-TRACK PARTS

Troubleshooting Guide

Special Notes

• The ZAX350-5 shares some undercarriage components with Komatsu PC350-8 (cross-reference possible)

• Always replace idler seals when servicing

• Consider replacing both idlers if one shows >50% wear

Need help with:

• Specific torque specs?

• Finding local suppliers?

• Exploded diagrams?

Provide your machine serial number (located on right frame near cab) for precise information!