Idler CAT 304 305 305.5 306 305.5e2 240-6304 241-5972 241-5973

Ensure precise track tension and stability for your excavator with the Idler CAT 304 305 305.5 306 305.5e2 from Big Power Parts. This heavy-duty front idler is engineered to guide rubber tracks, absorb shock, and maintain optimal tension, reducing undercarriage wear and ensuring smooth, reliable tracking across all ground conditions. Ideal for Australian construction, landscaping, and civil applications, this idler is a direct-fit replacement designed to match OEM specifications for simple bolt-on installation.

Constructed from high-strength steel, precision-forged and heat-treated, this idler withstands heavy front-end loads and abrasive terrain. The sealed, lubricated design keeps bearings running in oil within a fully enclosed hub, preventing contaminants from entering and ensuring long-term reliability. Smooth track guidance maintains proper alignment and reduces derailment risk, while even load distribution extends the life of your tracks, rollers, and sprockets.

Key Specifications

Machine Compatibility List

• Caterpillar 304
• Caterpillar 304 CR
• Caterpillar 304.5
• Caterpillar 305
• Caterpillar 305 CR
• Caterpillar 305.5
• Caterpillar 305.5E
• Caterpillar 305.5E2
• Caterpillar 306
• Caterpillar 306E

All idlers come with a 1-year warranty covering manufacturing defects, giving you confidence on every job site. To confirm the correct idler, verify your excavator's make, model, and serial number, then compare dimensions (overall diameter, center-to-center mount spacing, shaft diameter) against our specifications. If unsure, contact us with a photo of your current idler and machine ID plate for expert assistance. Fast shipping from Melbourne stock Australia-wide ensures you get the part quickly.