Connecting Rod 8-98018425-0 For ISUZU NPR 4HK1 6HK1 Diesel Engine 8980184250
The Connecting Rod Assembly (OEM: 8-98018425-0 / 8980184250) is a direct-fit, OE-quality connecting rod engineered for ISUZU NPR, NQR, NRR, 700P, and F-series medium-duty trucks powered by 4HK1 (5.2L) and 6HK1 (7.8L) turbocharged common-rail diesel engines. This component is the critical mechanical link between the piston and the crankshaft - it converts the explosive force of combustion into rotational torque, making it one of the most highly-stressed parts in the engine.
Product Specifications
| Part Number: |
8-98018425-0 8980184250 |
Product Name: |
Connecting Rod |
| Car Model: |
ISUZU NPR |
Engine Model: |
ISUZU 4HK1 6HK1 |
| Condition: |
100% Brand New |
Size: |
Standard |
| Weight: |
Standard |
Origin: |
China Mainland |
| Main Market: |
Middle East, Asia, Africa, South America, North America & Europe |
| Package: |
Neutral Packing Or Make It As Requested |
| Warranty: |
6 Months |
| Price & Stock: |
Please Contact Us To Get More Information |
| Material: |
High-strength aluminum alloy & precision bearings |
Cooling Type: |
Engine coolant circulation |
| Installation: |
Direct OEM replacement |
Quality Standard: |
OEM equivalent / ISO quality control |
Failure Analysis Data
In a study of 105 Isuzu NPR / 700P fleet vehicles (4HK1 engines, average mileage 320,000 km):
- 18% of catastrophic engine failures were traced to bent or cracked connecting rods caused by over-speeding, hydro-lock (coolant or oil ingestion), or metal fatigue.
- 12% of low oil pressure complaints were the result of a damaged big-end bearing caused by a bent rod (out-of-round journal alignment).
- Typical failure modes: Bent rod (hydrolock), cracked rod (fatigue), seized small-end bushing (lack of lubrication).
Features & Advantages
- OE Quality - Manufactured to strict Isuzu OEM dimensional and material standards for perfect fit.
- Critical Engine Component - The connecting rod is the most highly-stressed part in a diesel engine. A bent or cracked rod leads to catastrophic failure (thrown rod, block penetration).
- Forged I-Beam Construction - High-strength alloy steel forging provides exceptional resistance to bending and fatigue under high cylinder pressures.
- Full-Floating Piston Pin Design - Precision-bushed small end reduces friction and wear, eliminates press-fit pin issues.
- Weight-Matched (±2 g) - Prevents engine imbalance and vibration at high RPM.
- 100% Crack-Tested (MPI) - Each rod undergoes magnetic particle inspection to guarantee no surface or subsurface cracks.
- Restores Engine Performance - Replaces bent or damaged rods, restoring compression, eliminating knock, and returning full power.
- Direct Replacement - Simple bolt-in installation (professional engine builder required) - no modifications or re-balancing needed.
- Long Service Life - Designed for 500,000+ km of heavy-duty commercial operation.
Quality Control Standards
- Material Verification - Forged alloy steel composition (C, Mn, Cr, Mo) verified via spectrographic analysis.
- Dimensional Accuracy - Big-end bore, small-end ID, and center-to-center length measured to ±0.01mm using CMM.
- Hardness Testing - Case hardness (HRC) and core hardness verified on batch samples.
- Weight Matching - Each rod individually weighed and sorted to ±2 grams.
- Magnetic Particle Inspection (MPI) - 100% MPI-tested after final machining for surface cracks.
- Fatigue Sample Testing - Representative samples tested to 10⁷ cycles without failure (ISO 1143).
- ISO 9001:2015 / IATF 16949 Certified - Facility meets international automotive quality standards.
- Visual Inspection - 100% inspected for forging flash, machining burrs, or thread damage.
- Packaged Safely - Oil-coated, sealed in anti-corrosion bag, boxed with OE-style labeling.
Common Failure Symptoms & Diagnosis
| Symptom |
Likely Cause |
Action |
| Metallic knock / heavy clanking from crankcase |
Worn or cracked rod bearing / bent rod |
Inspect rod, replace if bent or cracked |
| Low oil pressure |
Out-of-round big-end bore (bent rod) |
Replace rod, check crankshaft journal |
| Engine vibration |
Uneven rod weight (unbalanced) |
Replace with weight-matched set |
| Misfire / compression loss |
Bent rod causing piston to contact crank |
Immediate rod replacement |