8A31-54-1140 Komatsu Rubber Cushion Damper — D155 Series Platform Mount
OEM-Equivalent • ISO 9001:2015 Certified • Komatsu D155A / D155AX • In Stock
What Is the 8A31-54-1140 Cushion Damper?
The 8A31-54-1140 is a rubber cushion damper engineered specifically for the Komatsu D155 bulldozer platform. Functioning as a critical vibration isolation component, it sits between the powertrain assembly and the main frame structure on D155A and D155AX series machines. Its primary role is to absorb and attenuate the mechanical vibrations generated by the engine and drivetrain during operation, preventing those forces from transferring directly into the chassis, undercarriage, and operator cab. Without a properly functioning cushion damper in this position, operators would experience significantly higher vibration levels, and surrounding structural components would be subjected to accelerated fatigue and premature failure.
The 8A31-54-1140 belongs to the 8A31-54 part family, which encompasses several cushion damper variants used across Komatsu's large dozer lineup. While it shares the same family designation as the 8A31-54-1130, the 1140 variant is designed for a different mounting position or configuration within the D155 platform. This distinction is important when ordering replacement parts: each mounting point on the D155 chassis has specific load-bearing requirements and geometric constraints, and installing the wrong variant can compromise both isolation performance and component longevity.
Operators running D155 machines in mining, heavy earthmoving, quarry operations, and large-scale road construction depend on properly functioning cushion dampers to extend the service life of adjacent components such as hydraulic lines, electrical connectors, and cab mounting hardware. The 8A31-54-1140 is manufactured using the same premium natural rubber compound and molding process employed across all parts in the 8A31-54 family, ensuring consistent mechanical properties and reliable performance across the full operating temperature range of the D155 platform.
Technical Specifications
| Property | Specification |
|---|---|
| Part Number | 8A31-54-1140 |
| OEM Brand | Komatsu |
| Type | Rubber Cushion Damper (Anti-Vibration Mount) |
| Equipment | Komatsu D155 Series, D155A, D155AX |
| Material | Natural Rubber (NR) Compound |
| Hardness | 55 ± 5 Shore A (ISO 48-4) |
| Tensile Strength | ≥ 12 MPa |
| Elongation at Break | ≥ 350% |
| Operating Temperature | −40°C to +90°C |
| Compression Set | ≤ 25% |
| Quality Certification | ISO 9001:2015 Certified |
| Availability | In Stock — Ships Worldwide |
Compatible Komatsu D155 Equipment
The 8A31-54-1140 cushion damper is designed for installation on the following Komatsu D155 series bulldozers:
- Komatsu D155A-2 — earlier generation D155A crawler dozer
- Komatsu D155A-3 — mid-generation with updated powertrain
- Komatsu D155A-5 — Tier 2 emission-compliant model
- Komatsu D155AX-5 — advanced cab and ROPS/FOPS configuration
- Komatsu D155AX-6 — Tier 3 model with improved fuel efficiency
- Komatsu D155AX-7 — Tier 4 Interim compliant platform
- Komatsu D155AX-8 — current production model with Tier 4 Final engine
Important: Always confirm your machine serial number against the Komatsu parts book before ordering. Serial number ranges determine the exact parts revision applicable to your specific unit, and some transitional builds may use different cushion configurations.
The Komatsu D155 is one of the most widely deployed large crawler dozers in the world. With an operating weight exceeding 40 tonnes and engine output in the 300+ horsepower range, the D155 platform is a workhorse in open-pit mining, large dam construction, highway grading, and bulk earthmoving projects across North America, South America, Africa, Australia, and Southeast Asia. The rubber cushion damper system on these machines plays an essential role in protecting both the operator and the machine itself from the significant vibration loads generated during continuous heavy-duty operation.
8A31-54-1140 vs. 8A31-54-1130 — Which One Do You Need?
One of the most common questions we receive is whether a D155 operator needs the 8A31-54-1140 or the 8A31-54-1130. Both part numbers belong to the same 8A31-54 family and both serve the D155 bulldozer platform, but they are not interchangeable. Each part is engineered for a specific mounting position with distinct load paths, bolt patterns, or dimensional profiles.
The 8A31-54-1130 is typically identified as the primary engine mount cushion on the D155 platform. It bears the direct weight and dynamic loads of the engine block and is usually located at the main engine-to-frame interface. The 8A31-54-1140, by contrast, generally serves as a secondary mount or transmission mount cushion, addressing vibration isolation at a different point in the powertrain support system. Because these positions experience different load magnitudes and vibration frequencies, the two parts may differ in geometry, durometer, or internal reinforcement even though they share the same base rubber compound.
The safest approach is to consult your Komatsu parts book (either the printed manual or Komatsu's online parts catalogue) and cross-reference the part number against your machine serial number. If you are performing a complete cushion damper overhaul on your D155, you may need both the 8A31-54-1130 and the 8A31-54-1140 along with any associated hardware. For smaller Komatsu D-series machines such as the D31EX through D85EX range, see the 8A31-54-1110 cushion damper instead.
Manufacturing Quality and Certifications
Every 8A31-54-1140 cushion damper we supply is produced in our ISO 9001:2015 certified manufacturing facility with over 25 years of specialized experience in industrial rubber compound engineering. Our quality management system covers every stage of production, from raw material incoming inspection through final product release.
Each individual 8A31-54-1140 unit undergoes a multi-point quality control process that includes Shore A hardness testing to verify the rubber compound falls within the specified 55 ± 5 Shore A range, dimensional inspection against Komatsu OEM drawings to ensure correct fitment, and visual quality control to identify any surface defects, voids, or bonding irregularities. Parts that do not meet all acceptance criteria are rejected and do not enter the finished goods inventory.
A Certificate of Conformance is available with every shipment upon request, documenting the production batch, test results, and traceability information. For fleet operators and mining companies that require additional documentation such as material safety data sheets (MSDS), tensile test reports, or compression set test certificates, we can provide these as part of our standard order fulfillment process.
Key Features & Benefits
Heavy-Duty Load Capacity
Engineered for the 40+ tonne Komatsu D155 platform, the 8A31-54-1140 supports the substantial static and dynamic loads generated by the 300+ horsepower SAA6D140E engine and torque converter assembly. The rubber compound's 55 Shore A durometer provides the stiffness needed to prevent excessive deflection under full-throttle operation while maintaining effective vibration isolation at idle and low-speed dozing.
Mining-Grade Durability
The D155 platform operates predominantly in harsh mining and heavy earthmoving environments. The 8A31-54-1140's rubber compound is formulated with enhanced oil and fuel resistance to withstand incidental contact with diesel, hydraulic fluid, and transmission oil that is unavoidable in the engine compartment of a working dozer. Anti-ozonant additives provide additional protection in electrically active mining environments.
Global Climate Compatibility
Operational from −40°C (Canadian oil sands, Siberian mining operations) to +90°C (engine bay peak temperatures in desert and tropical climates). The D155 is deployed worldwide — from Australian open-pit iron ore mines to African gold operations and South American copper sites — and the 8A31-54-1140 performs reliably across all of these temperature extremes.
Reduced Downtime Cost
A single D155 can move 1,000+ cubic meters of material per shift. Every hour of unplanned downtime represents significant lost production value. The 8A31-54-1140 is stocked and ships worldwide in 3–5 days, minimizing the time between failure detection and return to production. Volume discounts and scheduled blanket orders further reduce per-unit cost for fleet operators.
Performance Specifications
| Property | Specification | Test Method |
|---|---|---|
| Hardness | 55 ± 5 Shore A | ISO 48-4 |
| Tensile Strength | ≥ 12 MPa | ISO 37 |
| Elongation at Break | ≥ 350% | ISO 37 |
| Compression Set (24h @ 70°C) | ≤ 25% | ISO 815-1 |
| Tear Strength | ≥ 25 kN/m | ISO 34-1 |
| Accelerated Aging (72h @ 100°C) | Hardness change ≤ 8 IRHD | ISO 188 |
| Ozone Resistance (200 pphm, 48h) | No cracks at 20% strain | ISO 1431-1 |
| Operating Temperature | −40°C to +90°C | Continuous |
| Low-Temperature Flexibility | No brittleness at −40°C | ISO 812 |
Maintenance, Inspection & Expected Lifespan
The Komatsu D155 is a high-value capital asset generating substantial hourly production output. A failed or degraded 8A31-54-1140 cushion transmits raw engine and drivetrain vibrations directly into the chassis, accelerating fatigue in hydraulic line fittings, cab mounting brackets, structural welds, and electronic control modules. The cost of these cascading secondary failures vastly exceeds the cost of timely cushion damper replacement.
Inspection Schedule: Inspect all anti-vibration mounts on the D155 at every 2,000-hour major service interval. During inspection, examine the rubber surface for ozone-induced surface cracking (the characteristic “alligator skin” pattern), measure the cushion's free height against the original dimension to quantify compression set, check for oil or fuel contamination that causes swelling and softening, and verify that all mounting hardware remains at the correct torque value. Record findings in the machine's maintenance log for trend analysis across service intervals.
Replacement Criteria: Replace the 8A31-54-1140 if: (1) surface cracks penetrate deeper than 2 mm, (2) permanent compression set exceeds 30% of original free height, (3) rubber surfaces show visible swelling or softening from oil contamination, (4) the operator reports increased cab vibration during normal operation, or (5) mounting hardware shows signs of fretting or elongation at bolt holes. Under standard mining and heavy earthmoving duty cycles (12–20 operating hours per day), expect a service life of 4,000 to 8,000 operating hours.
Complete Overhaul Note: When performing a full powertrain mount overhaul on the D155, replace all cushion dampers simultaneously — including the 8A31-54-1130 primary mount and the 8A31-54-1140 secondary mount. Mixing new and worn cushions at different mounting positions creates uneven load distribution and can cause premature failure of the new components. Contact us for complete D155 cushion overhaul kits with volume pricing.
Shipping and Ordering
The 8A31-54-1140 is in stock and ready to ship. Standard worldwide delivery takes 3 to 5 business days via international express courier. We ship to the United States, Canada, Australia, South Africa, Chile, Peru, Indonesia, and over 60 additional countries where Komatsu D155 dozers are in active service.
All shipments include full commercial documentation: commercial invoice, packing list, and the correct HS (Harmonized System) code for customs clearance in your destination country. For shipments to the USA and Canada, we can also provide a NAFTA/USMCA certificate of origin if required by your import broker.
Volume discounts are available for fleet operators, Komatsu dealerships, and independent parts distributors ordering multiple units or placing scheduled blanket orders. Contact us for pricing — we guarantee a 24-hour quote response on all inquiries.