Segment 17M-27-41630 D275A-5 for KOMATSU Dozer Tractor Machine/OEM Forged Segment Group manufactures in quanzhou China
Product Specifications
The Komatsu D275A-5 Segment Group refers to the track chain assembly - a core wear component of the bulldozer's undercarriage system. It's a critical, high-wear item requiring periodic replacement.
Here's a detailed breakdown of its components and key information:
Core Components of the Segment Group:
Track Links (Segments): Forged steel links forming the chain. Includes:
Inner Links: Fit inside the track shoe.
Outer Links: Fit outside the track shoe.
Track Bushings (or "Bore"): Hardened steel cylinders pressed into the outer links. The sprocket teeth engage with these bushings to drive the track.
Track Pins: Hardened steel pins connecting the inner and outer links through the bushings. They allow the chain to articulate.
Track Bolts & Nuts: High-strength fasteners used to secure the track shoes to the track links.
Key Specifications (General - ALWAYS Verify by S/N):
Pitch: The distance between the centers of two adjacent track pins. For the D275A-5, this is typically 216mm (8.5 inches). This is the most critical dimension.
Shoe Width: The width of the track shoe that mounts onto the links. Common widths for the D275A-5 are 610mm (24") or 760mm (30"), depending on configuration (swamp pads might be wider).
Number of Links per Chain: Determined by the machine's track frame length and shoe width. Significantly impacts total cost.
Bushing OD (Outside Diameter): Critical for sprocket engagement.
Pin Diameter: Critical for link fit and wear.
Material & Hardness: High-quality, heat-treated alloy steel (often SAE 4130/4140 equivalents). Bushings and pins are induction hardened to extreme surface hardness (often 55-60 HRC) for wear resistance. Links are tough to withstand impact.
Function & Importance:
Forms the foundational "chain" that connects the track shoes.
Transmits the driving force from the sprocket to the ground via the shoes.
Supports the immense weight of the machine.
Articulates to allow the track to go around the idler and sprocket.
Wear: The pins rotating inside the bushings (and sometimes the link bores) is the primary wear point. As they wear, the chain "grows" (pitch increases), leading to poor sprocket engagement, accelerated wear on other undercarriage components (sprocket, idler, rollers), reduced efficiency, and potential derailment.
Critical Considerations for Replacement:
Serial Number Dependency: Undercarriage components are HIGHLY dependent on the specific machine serial number. Minor design changes occur during production. ALWAYS use your machine's S/N to look up the correct part numbers.
Wear Matching (Crucial!): Replacing only the segment group is not recommended unless the sprocket and idler are nearly new. A worn sprocket or idler will rapidly destroy a new chain (and vice-versa). For optimal lifespan and cost-effectiveness, replace the Segment Group (Chain), Sprocket Segments/Rims, and Idler as a matched set.
Shoe Compatibility: Ensure the new segment group matches the bolt pattern and width of your existing track shoes (unless replacing shoes too).
Quality Tiers:
OEM (Komatsu): Highest guaranteed fit, performance, and longevity. Highest cost.
Premium Aftermarket (e.g., Berco, ITM, Prowler, DRB): Often comparable quality to OEM at a lower price. Reputable brands offer excellent value.
Standard Aftermarket: Variable quality. Can be cost-effective for light-use machines but may have significantly shorter life.
Sealed vs. Dry Chain: Most modern chains for machines like the D275A-5 are Sealed and Lubricated Track (SALT or LRT). The pin/bushing joint is sealed and packed with lubricant, greatly extending life and reducing friction/heat. Some older or economy options might be dry.
Where to Find Specific Part Numbers & Order:
Komatsu Parts Manual (PEN): The definitive source for the exact OEM part numbers required for your specific D275A-5 serial number. Contains diagrams and parts lists.
Komatsu Dealer: Provide your machine model and serial number for OEM parts quotes and expert advice.
Reputable Undercarriage Specialists: Major suppliers have extensive databases. Provide model (D275A-5), serial number, and ideally your current chain pitch measurement. They can cross-reference OEM numbers and offer quality aftermarket alternatives.
In Summary:
The Komatsu D275A-5 Segment Group is the heavy-duty track chain assembly, comprising forged links, hardened bushings and pins, and fasteners. Its key specs are the 216mm pitch and shoe width (typically 610mm or 760mm). It's a major wear item requiring replacement as part of a matched set (with sprocket and idler) for best results. Always identify the correct parts using your specific machine serial number due to potential variations. Choose quality (OEM or premium aftermarket) appropriate for your application and budget. Proper maintenance (cleaning, correct tension) extends its life significantly.
