D375A-5 Komatsu Bulldozer Track Carrier Roller Forged 40Mn2 Steel Induction Hardened HRC 50-56 Undercarriage Part

This YT D375A-5 track carrier roller is a heavy-duty top roller designed for the Komatsu D375A-5 crawler bulldozer, a machine commonly assigned to mining dozing and mass earthmoving. Sitting on the upper frame of the track assembly, the carrier roller guides the return run of the track chain and stops it from sagging between the sprocket and the idler, which keeps travel smooth and protects the chain from snap loads during reverse operation.

The roller body is forged from 40Mn2 alloy steel with 50Mn available on request, then quenched, tempered and induction hardened to HRC 50-56 on the tread surface. YT manufactures the D375A-5 carrier roller as a drop-in assembly: the shaft, flanges, bushings and seals are matched to the original mounting envelope, so mechanics can fit it with standard hand tools and without modifying the frame bracket.

Main Types of Carrier Rollers Key Features

• High-strength alloy forging: the 40Mn2 body blank is forged in closed dies to align grain flow with the stress paths of the roller.
• Deep case hardening: induction hardening takes the surface to HRC 50-56, giving excellent resistance to chain link wear.
• Balanced core toughness: the quench and temper cycle leaves a ductile core that survives shocks from hard rock and cold climates.
• Positive sealing: heavy-duty seal rings keep grease inside the roller and keep mud, dust and water away from the bushings.
• Controlled geometry: every roller is machined and ground to the D375A-5 track dimensions with documented tolerances.
• Service-friendly design: the assembly can be stripped, re-bushed and rebuilt, extending the life of the original shell.

Main Dimensions of Installation

The models above are just for reference, we can't list all models here. We can supply more products as your requirements. Please feel free to send us your inquiry.

*Values are reference; OEM part number confirmation advised before ordering.

*Values are reference; OEM part number confirmation advised before ordering.

Production Process

1. Incoming 40Mn2 bars are checked with a spectrometer so that every heat matches the required manganese and carbon ranges.
2. The heated billet is shaped in closed forging dies to form the roller profile with a continuous grain structure.
3. A normalize treatment refines the grain, followed by oil quenching and tempering to set the core hardness.
4. CNC lathes cut the bore, the outer race and the flange faces using the D375A-5 dimensional drawing.
5. The race area is hardened by medium-frequency induction coils and immediately quenched for a consistent case depth.
6. Grinding brings the race to the final diameter and surface finish required for quiet chain travel.
7. Clean-room assembly presses in the bushings, fits the shaft and installs the seal package.
8. Each roller is checked for hardness, surface cracks and final dimensions, with records kept per batch.
9. After oiling, rollers are wrapped and placed onto export pallets ready for container loading.

Factory Strength

YT is the brand of XIAMEN YINTAI MACHINERY CO., LTD., a Fujian-based manufacturer and exporter established in 2011 with ISO 9001:2015 certification. The plant combines a forging workshop, CNC machining section and dedicated heat treatment line, so the Komatsu D375A-5 carrier roller passes through every stage in-house. This vertical setup lets the quality team trace each roller back to its steel heat and process record.

With a workforce of 50-100 people and annual sales between USD 10-20 million, roughly 90-100% of which comes from export business, the company supplies undercarriage components to dealers and contractors across the globe. YT accepts OEM/ODM projects, arranges SGS or third-party inspection on request, and publishes realistic lead times so customers can plan their maintenance stops.

• Hard rock mining fleets: rollers supplied with the harder HRC 50-56 case and reinforced seals for abrasive ore and waste haulage roads.
• Rebuild workshops: YT offers bare shells and full assemblies so service shops can choose between quick exchange and in-house rebuilds.
• Cost control programs: fleets replace factory rollers with YT equivalents at a lower landed cost while keeping the same hardness specification.
• Consignment stock: for remote mine sites, YT can arrange staged deliveries so rollers arrive just before the scheduled service window.
• Quick dispatch: D375A-5 carrier rollers in the fast-moving range are pre-built and can leave the warehouse within days of order confirmation.

Komatsu D375A-5 bulldozers equipped with YT carrier rollers are typically found in surface mines, dam construction, land reclamation and large infrastructure projects where the dozer pushes heavy material over long distances. The carrier roller holds the upper chain taut so that the track stays aligned with the sprocket, reducing side wear on pins and bushings. Operators also fit YT rollers during full undercarriage overhauls, combining them with YT track shoes, links and idlers for a matched set.

Compatible Brands Frequently Asked Questions

Q1: Which measurements do you need to confirm fitment for my D375A-5?

Please measure the outer diameter, overall width, shaft bore and the distance between the mounting brackets of your current roller. Photos of the worn part speed up the check considerably.

Q2: How does YT compare with the original Komatsu roller?

YT rollers are aftermarket equivalents built to the same dimensional and hardness targets. They are not branded as Komatsu parts, and we recommend confirming the OEM part number before you order.

Q3: What service life can I expect from a hardened carrier roller?

Life depends on ground conditions, track tension and maintenance. In normal mining dozing with correct tension, the hardened race typically wears slowly and the roller can be rebuilt once or twice.

Q4: Do you support sample orders and small quantities?

Yes, the minimum order is a single piece. Sample orders are welcomed for evaluation, and the sample value is deducted from your first regular order.

Q5: How are the rollers shipped and what warranty applies?

Rollers go by sea freight on steel or wooden pallets with anti-rust protection, or by air for urgent needs. YT warrants the rollers for 12-18 months against manufacturing defects.

Every D375A-5 carrier roller is oiled, wrapped in corrosion-resistant film and packed in sturdy steel or wooden pallets designed for container shipping. Dimensional inspection, hardness verification and seal checks are carried out on 100% of production, and batch records can be supplied to buyers or third-party inspectors. YT supports SGS inspection at the factory and provides OEM/ODM packaging for distributors who sell under their own brand.

Why Choose Us?

• Through quench-tempering processes to ensure excellent mechanical properties, high strength and superior wear resistance to bending and breakage.
• Advanced Germany KUKA automatic machining center, horizontal and vertical CNC machining ensure the accuracy of assembly dimensions. This is to maximize the life span of each component and minimize production cost.
• MAKZAK Precison Finishing Machinery from Japan makes sure we have steady and good welding quality.
• We have complete production line and professional designers and working team. We can also produce any requested parts according to your blue print or samples.