Oil Pump Assembly 8-98128134-0 8-97381553-3 For ISUZU NLR85 NMR85 4JJ1T Diesel Engine 8981281340 897381553

The Oil Pump Assembly (OEM Numbers: 8-98128134-0 / 8-97381553-3 / 8981281340 / 897381553) is a premium-quality, direct replacement engine lubrication component designed specifically for ISUZU NLR85, NMR85, and NNR series trucks equipped with 4JJ1T 3.0L turbo diesel engines. This mechanical gear-type oil pump is the heart of the engine's lubrication system. Driven by the crankshaft, it draws oil from the sump through the pickup tube and delivers it under pressure to the crankshaft bearings, camshaft bearings, cylinder walls, piston cooling jets, and turbocharger oil feed circuit. Proper oil pressure is essential for reducing friction, dissipating heat, and preventing premature wear or catastrophic engine failure.

Function: The oil pump assembly pressurizes and circulates engine oil to lubricate and cool moving parts, maintaining proper oil pressure for reliable engine operation in ISUZU NLR85 4JJ1T diesel engines.

• OE Quality: Manufactured to strict ISUZU dimensional and material specifications for perfect fit and function.
• High-Efficiency Gear Set: Precision-machined internal gears provide consistent oil pressure and flow rate.
• Durable Construction: Heavy-duty die-cast aluminum housing and hardened steel internals withstand high pressures and temperatures.
• Integrated Relief Valve: Controls oil pressure at high RPM to protect seals and prevent over-pressurization.
• Restores Engine Lubrication: Eliminates low oil pressure, lifter ticking, bearing knock, and turbo wear caused by a failing oil pump.
• Direct Replacement: Matches OE mounting flange, drive interface, and oil line connections for simple installation.
• Long Service Life: Engineered for light-duty commercial diesel engine duty cycles and extended service intervals.
• Cost-Effective Repair: Affordable replacement that prevents costly engine damage.
• Essential Engine Component: Critical for maintaining proper oil circulation, cooling, and engine longevity.

This oil pump assembly is specifically designed for ISUZU light-duty trucks and commercial vehicles. Common applications include:

• ISUZU NLR85 (Light-Duty Trucks)
• ISUZU NMR85 (Light-Duty Trucks)
• ISUZU NNR (Light-Duty Trucks)
• ISUZU N Series (NH, NK, NM — as applicable)

• ISUZU 4JJ1T — 3.0L Inline-4 Turbo Diesel
• Displacement: 2.999L
• Application: Light-duty trucks and commercial vehicles

1. Ensure engine is cool — Allow the engine to cool completely before disassembly.
2. Disconnect battery — Always disconnect the negative terminal before working.
3. Drain engine oil — Drain the engine oil into a suitable container.
4. Remove the oil pan — Remove the oil pan to access the oil pump and pickup tube.
5. Remove the old oil pump — Unbolt the old oil pump from the engine block; note the drive engagement and gasket arrangement.
6. Clean all mating surfaces — Thoroughly clean the engine block and pump mating surfaces; remove all old gasket material and debris.
7. Inspect related components — Check the oil pickup tube, O-ring, relief valve, and drive components for wear or damage; replace if necessary.
8. Prime the new oil pump — Fill the new pump with clean engine oil and rotate the drive to prime it before installation.
9. Install the new oil pump — Position the new oil pump on the block; align bolt holes and drive engagement.
10. Install mounting bolts — Hand-start all bolts; tighten to manufacturer torque specifications.
11. Reinstall the oil pan — Install a new oil pan gasket and reinstall the pan; torque bolts to specification.
12. Refill with engine oil — Fill with the correct grade and quantity of engine oil.
13. Prime the oil system — Crank the engine without starting (if possible) to prime the oil pump.
14. Start and test — Start the engine; verify proper oil pressure with a gauge and check for leaks.
15. Road test — Test drive to verify proper engine operation and no abnormal noise or leaks.

• Material Verification: Confirms aluminum housing and steel gear composition meet ISUZU strength and durability specifications.
• Dimensional Inspection: Housing dimensions, mounting flange, bolt hole pattern, and gear profile verified within OEM tolerances.
• Gear Tooth Inspection: Internal gear set checked for proper mesh and surface finish.
• Rotational Torque Testing: Each pump tested to ensure rotating torque is within specification.
• Leak Testing: Pump housing and seals tested for leak-proof integrity.
• Relief Valve Testing: Integrated relief valve tested for proper opening pressure.
• Visual Inspection: 100% checked for casting defects, machining flaws, or damage.
• Packaged Safely: Protected and packaged to prevent damage during transit.

• Neutral export packing or customized packaging available
• Carton or wooden case for safe transportation
• Fast delivery for stock items
• Shipping by Express Air or Sea

For pricing, availability, or bulk purchase of the Oil Pump Assembly 8-98128134-0 8-97381553-3 For ISUZU NLR85 NMR85 4JJ1T Diesel Engine 8981281340 897381553, please contact our sales team for a competitive quote and expert technical support.