ISUZU 4BD1 Crankshaft 5123101631 - Forged Steel Engine Core Component with Dynamic Balance Tested and CE Certified
Basic Properties
Place of Origin:
CHINA
Brand Name:
YIMI
Certification:
ISO/TS16949
Model Number:
NPR59 4BD1
Trading Properties
Minimum Order Quantity:
20 PCS
Price:
Negotiable
Payment Terms:
T/T
Supply Ability:
10000 pcs/month
Specifications
| Material: | Forged Steel / Ductile Cast Iron | Net Weight: | 35.5 Kg |
| Engine Displacement: | 4.0L | Cylinders: | 4 Cylinders |
| Overall Length: | 647.5mm | Main Journal Diameter: | 80mm |
| Connecting Rod Journal Diameter: | 64mm | Dynamic Balance: | G6.3 Grade (ISO 1940) |
| High Light: | Forged Steel Crankshaft,Dynamic Balance Tested Engine Core Component,CE Certified ISUZU 4BD1 Part |
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Product Description
ISUZU Crankshaft 5123101631 5-12310163-1 for NPR59 4BD1 — OEM Standard Engine Core Component
ISUZU Crankshaft 5123101631 5-12310163-1 Compatible with NPR59 4BD1 Diesel Engine — Forged Steel Engine Core Component
Numbering Note: This product number is 5123101631 / 5-12310163-1. The series also includes 5123101630 / 5-12310163-0 and 5123101891 / 5-12310189-1. Please verify the specific number based on actual vehicle configuration.
Working Principle
The crankshaft is one of the most heavily loaded components in the engine, connected to the pistons via connecting rods. Its working principle includes:
- Power Conversion: During the engine's power stroke, combustion pressure pushes the piston downward, converting reciprocating motion into rotational motion through the connecting rod.
- Power Output: The crankshaft transmits rotational power through the flywheel to the clutch, transmission, and ultimately to the wheels.
- Balance: Counterweights on the crankshaft offset the reciprocating inertia of the pistons and connecting rods, reducing engine vibration.
- Accessory Drive: The front of the crankshaft drives the timing system, water pump, alternator, A/C compressor, and other accessories via belts/gears.
Failure Symptoms
⚠️ Inspect immediately if any of these occur
| Symptom | Probable Cause |
|---|---|
| Severe engine vibration, especially at specific RPM ranges | Bent crankshaft or damaged counterweights; loss of dynamic balance |
| Heavy "knocking" sound from engine (main bearing noise) | Worn main bearing journals; excessive main bearing clearance |
| Consistently low oil pressure | Worn crankshaft journals causing increased oil leakage |
| Crankshaft pulley wobbles noticeably | Bent crankshaft front end or damaged harmonic balancer |
| Engine fails to start or suddenly stalls | Broken crankshaft; severe internal engine damage |
Verifiable Data
✅ Product Net Weight: 35.5 kg — verified by ISO-standard bench scale testing.
✅ Material Standard: Manufactured from Forged Steel or Ductile Cast Iron — meets ISUZU 4BD1 engine original specifications.
✅ Precision Machined Dimensions: Main journal diameter 80mm, connecting rod journal diameter 64mm, overall length 647.5mm — inspected by CMM, compliant with ISO 2768-m tolerance class.
✅ 100% Dynamic Balance Tested: Every crankshaft undergoes precision dynamic balance testing before shipment — ensuring smooth high-speed operation and reduced engine vibration.
✅ OE Cross-Reference Verified: Replaces OEM numbers 5-12310163-1, compatible with 5-12310163-0, 5123101630, 5123101891, 5-12310189-1 and other numbers.
✅ Certification: CE certified.
✅ Warranty: 1 year.
✅ HS Code: 848310000.
OE Cross-Reference
| Type | Number |
|---|---|
| ISUZU OEM | 5123101631 / 5-12310163-1 |
| Same Series | 5123101630 / 5-12310163-0 |
| Alternative | 5123101891 / 5-12310189-1 |
| Related | 5-12310-163-1, 5-12310-163-0 |
Product Specifications
| Part Number: | 5123101631 5-12310163-1 | Product Name: | Crankshaft |
| Car Model: | NPR59 | Engine Model: | 4BD1 |
| 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 | ||
Vehicle & Engine Compatibility
Primary Vehicle Applications:
| Brand | Model | Chassis | Engine | Notes |
|---|---|---|---|---|
| ISUZU | NPR59 | NPR59 | 4BD1 | Light/medium-duty truck |
| ISUZU | NPR | NPR | 4BD1 | Light/medium-duty truck |
| ISUZU | NQR | NQR | 4BD1 | Medium-duty truck |
| ISUZU | NKR | NKR | 4BD1 | Light-duty truck |
| ISUZU | NHR | NHR | 4BD1 | Light-duty truck |
Important Fitment Warnings
- Number Confirmation: This product number is 5123101631 / 5-12310163-1. The series also includes 5123101630 / 5-12310163-0 and 5123101891 / 5-12310189-1. Verify the specific number on the engine nameplate before ordering.
- Associated Components: When replacing the crankshaft, it is recommended to replace main bearings, connecting rod bearings, and front/rear crankshaft seals simultaneously — ensures reliability and service life after engine overhaul.
- Installation Torque: Refer to ISUZU 4BD1 engine factory workshop manual for main bearing cap and connecting rod bolt torque specifications.
- Bearing Selection: Crankshaft journal sizes are available in standard (STD) and oversized (0.25mm, 0.50mm, etc.) grades. Measure actual journal dimensions before selecting bearings.
- Professional Installation: Crankshaft replacement is a core engine overhaul procedure requiring complete engine disassembly and reassembly. Must be performed by a qualified engine repair technician.
Features & Benefits
High-Quality Forged Steel/Ductile Cast Iron Material
Excellent fatigue strength and wear resistance for long-term reliable operation under high-speed, high-load conditions — suitable for ISUZU 4BD1 4.0L diesel engine and Hitachi excavator applications.
Precision-Machined Dimensions (Main Journal 80mm / Rod Journal 64mm / Overall Length 647.5mm)
Ensures precise fit with main and connecting rod bearings — provides stable rotational support and proper lubrication clearance — inspected by CMM, compliant with ISO 2768-m tolerance class.
100% Dynamic Balance Tested
Every crankshaft undergoes precision dynamic balance testing — ensures smooth high-speed engine operation; significantly reduces vibration and noise; extends engine service life.
CE Certified & 1-Year Warranty
Internationally recognized quality certification ensuring compliance with European safety, health, and environmental standards — CE certified; reliable after-sales protection — 1-year quality guarantee.
Broad OEM Cross-Compatibility
Replaces OEM numbers 5123101631 / 5-12310163-1; compatible with 5123101630, 5123101891 and other numbers — fits NPR59, NPR, NQR, NKR trucks and Hitachi EX100/EX120 excavators.
Packaging & Supply
| Packaging | Neutral packaging or customized per customer request |
| Quantity per package | 1 pc/carton |
| Net Weight | 35.5 kg |
| Customization Options | OEM custom packaging / neutral packaging / private labeling |
| Minimum Order Quantity | 1 piece |
| Warranty | 1 year |
| HS Code | 848310000 |
| Target Customers | Truck parts wholesalers, engine overhaul shops, fleet purchasers, export traders |
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