ISUZU 4JB1 Oil Pump Assembly - OE Quality Direct Replacement with Hardened Steel Gears and Chain-Driven Reliability

The engine oil pump pressurizes and circulates lubricating oil to critical moving parts (crankshaft, camshaft, bearings, piston cooling jets). It maintains stable oil pressure across all engine speeds, preventing metal-to-metal contact and ensuring long-term engine reliability.

The Engine Oil Pump Assembly (OEM Numbers: 8-97033175-0, 8-97385984-0 / 8970331750, 8973859840) is a premium-quality, direct replacement lubrication component engineered specifically for the legendary ISUZU 4JB1 2.8L diesel engine, the workhorse found in ISUZU NKR55, NKR58, NHR, NPR, 100P, ELF series light trucks, as well as TFR/TF pickups, D‑MAX (early), JMC (Jiangling) JX493, Hitachi EX/ZAXIS, Kobelco SK, Kato HD series and industrial applications.

• OE Quality: Manufactured to strict ISUZU OEM dimensional and material standards for perfect direct-fit replacement
• Gear-Type Pump Design: Precision-machined gear-type design delivers consistent flow with minimal pulsation
• Integrated Pressure Relief Valve: Factory-calibrated spring-loaded pressure relief valve prevents over-pressurization
• Chain-Driven Reliability: Driven directly from crankshaft via timing chain for immediate oil pressure and zero maintenance
• Hardened Steel Gears: Case-hardened steel gears resist wear, pitting, and spalling for extended service life
• Restores Factory Oil Pressure: Replaces worn components to restore consistent oil pressure at idle and under load
• Prevents Catastrophic Engine Failure: Protects against bearing failure and turbocharger damage
• Direct Replacement: Simple bolt-on installation with no modifications required
• Cross-Platform Compatibility: Fits wide range of Isuzu N-series trucks, TFR pickups, and industrial equipment
• ISO 9001:2015 / IATF 16949 Certified: Manufactured under strict automotive quality management standards
• Long Service Life: Designed for 500,000+ km of heavy-duty commercial operation

• Material Verification: Housing composition and gear steel tested to JIS/SAE durability standards
• Dimensional Accuracy: Verified against OE blueprints using CMM equipment (±0.01 mm tolerance)
• Gear Clearance Inspection: Radial clearance, axial clearance, and backlash measured for optimal performance
• Pressure Relief Valve Calibration: 100% tested on flow bench for correct pressure and flow rates
• Hardness Testing: Gear teeth verified using Rockwell hardness testers
• Durability Testing: Accelerated life-cycle testing validates long-term reliability
• Leak Testing: 100% pressure-tested to guarantee no internal or external leakage
• Vibration & Thermal Cycling Test: Validates reliability in various operating environments
• Visual Inspection: 100% inspected for manufacturing imperfections
• Safe Packaging: Anti-corrosion coated and sealed in moisture-barrier VCI bags

• Individual Packaging: Anti-corrosion coated, sealed in VCI bags with OE-style labeling
• Wholesale / Bulk Orders: Available in case packs of 5, 10, 20, 50 units with pallet pricing
• Customization: Private-label retail packaging available for volume orders
• Fast Shipping: Ready stock for immediate dispatch worldwide
• Wholesale Support: Long-term supply agreements and tiered commercial pricing