Product Overview — Part 8A31-54-1140
The 8A31-54-1140 is a precision-manufactured Cab Mounts component. The 8A31-54-1140 rear cab isolation mount is the rear-position component for Hitachi ZX series excavator cab systems. Rear cab mounts typically carry a higher proportion of the cab static weight due to the Hitachi ZX cab's rearward center of mass, and also see the highest dynamic loads during machine swing deceleration. Engineered with sufficient axial (vertical) compliance to provide vibration isolation while maintaining adequate lateral and fore-aft stiffness to control cab movement during dynamic operations. The rubber compound provides at least 10 dB of isolation at the Hitachi engine's primary vibration frequency. Part 8A31-54-1140 completes the Hitachi ZX cab mount system with 8A31-54-1110 (standard) and 8A31-54-1130 (front). All three Hitachi parts are stocked at our facility and available for fast dispatch to US customers. Certificate of conformance included with every shipment.
Technical Specifications
| Property | Value | Standard |
|---|---|---|
| Part Number | 8A31-54-1140 | OEM Specification |
| Hardness | 45–70 Shore A (application specific) | ISO 48-4 / ASTM D2240 |
| Tensile Strength | ≥ 16 MPa | ISO 37 / ASTM D412 |
| Elongation at Break | ≥ 300% | ISO 37 / ASTM D412 |
| Compression Set | ≤ 25% (22h/70°C) | ISO 815-1 / ASTM D395 |
| Temperature Range | −40°C to +90°C | Operational limits |
| Ozone Resistance | No cracking 168h | ISO 1431-1 |
| Fire Safety | EN 45545-2 HL2/HL3 available | EN 45545-2:2013 |
| Fatigue Life | > 1,000,000 cycles | Dynamic fatigue protocol |
Applications
Hitachi ZX200, ZX225, ZX270, ZX300, ZX350, ZX400 excavator rear cab mounts; Hitachi EX series rear cab isolation.
Our technical team can assess suitability for other equipment types. Contact us with the make, model, and serial number for a precise cross-reference confirmation.
Material & Quality Standards
- Base Polymer: Natural Rubber (NR) or NR/SBR blend — excellent resilience and fatigue resistance
- Reinforcing Fillers: High-structure carbon black for controlled stiffness and wear resistance
- Protection Additives: Anti-ozonant wax and chemical antioxidant for extended outdoor service life
- Bonding System: Chemically bonded rubber-to-metal interface exceeding bulk rubber strength
- EN 45545-2 Option: Halogen-free flame retardant meeting smoke toxicity requirements (on request)
Every batch produced under ISO 9001:2015 QMS with full material traceability. Certificate of Conformance and material test reports available upon request.
Installation Guidelines
- Inspect on arrival: Verify part number 8A31-54-1140. Check for transit damage — reject any non-conforming component.
- Clean mating surfaces: Remove all rust, old rubber fragments, grease, and paint before installation.
- Align correctly: Follow assembly drawing orientation. Incorrect orientation may cause premature failure.
- Torque fasteners: Use calibrated torque wrench and cross-pattern tightening sequence per OEM specification.
- Post-install check: Inspect for correct seating. Run equipment at low speed to verify no abnormal noise or vibration.