ISUZU Forged Alloy Steel Crankshaft 647.5mm Overall Length with 76mm Main Journal Diameter for NPR 4BE1 Engine

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, and other accessories via belts/gears.

⚠️ Inspect immediately if any of these occur:

Primary Vehicle Applications:

Primary Engine Applications:

Installation Guidelines (Reference Workshop Manual):

Preparation:

• Confirm engine model (4BE1) and part number (8-94416373-2)
• Prepare tools: Torque wrench, micrometer, Plastigauge, crankshaft lifting sling
• Recommended to also prepare: Main bearings, connecting rod bearings, front/rear crankshaft seals, sealant

Removing Old Crankshaft (Reference Steps):

1. Remove the engine from the vehicle and place on an engine repair stand.
2. Remove flywheel, clutch pressure plate (if equipped), timing gears/chain.
3. Remove oil pan and oil pump.
4. Remove main bearing caps in sequence, mark each cap's position and orientation.
5. Carefully remove the old crankshaft.

Installing New Crankshaft (Installation Sequence):

1. Inspect new crankshaft: Check all journal surfaces for scratches, rust, or defects.
2. Clean: Thoroughly clean crankshaft journals, main bearing saddles, and caps.
3. Install main bearings: Install bearings into saddles and caps — note bearing orientation.
4. Lubricate: Apply engine oil to bearings and crankshaft journals.
5. Install crankshaft: Carefully lower the crankshaft into the main bearing saddles.
6. Install main bearing caps: Install caps in their marked positions; torque bolts to specification in correct sequence.
7. Check crankshaft rotation: Rotate manually — confirm smooth operation, no binding.
8. Measure bearing clearance: Use Plastigauge to confirm main and rod bearing clearance is within specification.
9. Install front/rear crankshaft seals: Install new front and rear crankshaft seals.
10. Install timing system: Install timing gears/chain per timing marks — ensure correct valve timing.
11. Install remaining components: Install oil pump, oil pan, flywheel, and other components in sequence.

Post-Installation Checks (Mandatory):

• Rotation check: Rotate crankshaft manually — confirm smooth operation, no binding.
• Timing check: Confirm crankshaft timing marks align with camshaft timing marks.
• Start test: Start engine; check for abnormal noise and oil leaks.

Maintenance Schedule: