Honda OEM K-Series 4.5x21mm Crankshaft Pulley Key
Part Number: 90704-PNA-000

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Product Details

The Honda OEM Crankshaft Pulley Key is a genuine factory replacement designed to maintain proper alignment between the crankshaft and crankshaft pulley on compatible Honda and Acura engines. This small but essential component, commonly referred to as a Woodruff key, helps accurately position the crankshaft pulley during installation.

Manufactured to Honda's original equipment specifications, this precision-engineered key measures 4.5mm x 21mm and provides the correct factory fit for applications requiring part number 90704-PNA-000.

The crankshaft pulley key fits into a machined slot in the crankshaft and engages the corresponding keyway in the crankshaft pulley. This ensures that the pulley is correctly indexed during assembly.

During crankshaft pulley removal, timing chain service, oil pump replacement, or engine rebuilding, the original key can become damaged, worn, or lost. Replacing a damaged crankshaft key with a genuine Honda component helps restore the original alignment configuration and ensures proper assembly.

Whether you're rebuilding a K20 or K24 engine, installing an upgraded crankshaft pulley, or completing a Honda engine swap, this genuine Honda OEM Crankshaft Pulley Key is an excellent replacement for the original factory component.

Features

Genuine Honda OEM Part: Authentic factory replacement manufactured to Honda's original equipment specifications.
Crankshaft Pulley Key: Designed to accurately index the crankshaft pulley to the crankshaft.
Woodruff Key Design: Fits into the factory crankshaft keyway for proper component alignment.
4.5mm x 21mm Dimensions: Factory-specified key size for compatible applications.
Direct OEM Replacement: Replaces the original crankshaft key where Honda specifies part number 90704-PNA-000.
Precision-Machined Construction: Provides accurate fitment within the corresponding crankshaft and pulley keyways.
Durable Metal Construction: Designed for dependable performance in its intended engine application.
K-Series Engine Compatibility: Fits numerous Honda and Acura K20 and K24 engine configurations.
Ideal for Engine Rebuilding: Excellent for crankshaft pulley replacement, timing system service, and complete engine rebuilds.
Performance Build Friendly: Suitable for compatible naturally aspirated, turbocharged, and supercharged engine builds.
Sold Individually: Includes one genuine Honda crankshaft pulley key.
OEM Part Number: 90704-PNA-000.

Additional Information

Manufacturer: Honda / Acura
Part Number: 90704-PNA-000
OEM Description: Key (4.5x21)
Other Names: Crankshaft Key / Crank Pulley Key / Woodruff Key / Crankshaft Pulley Woodruff Key
Product Type: Engine Rotating Assembly Hardware
Dimensions: 4.5mm x 21mm
Installation Location: Crankshaft Pulley Keyway
Material: Metal
Quantity: Sold Individually (1 Key)

Common Reasons for Replacement

Crankshaft pulley keys should be inspected whenever the crankshaft pulley is removed.
Damaged or worn original crankshaft key
Deformed or sheared key
Missing factory crankshaft key
Damage during crankshaft pulley removal
Crankshaft pulley replacement
Harmonic balancer replacement
Timing chain or timing cover service
Oil pump replacement
K20/K24 engine rebuilding
Engine swap preparation
Performance engine assembly
Replacing a damaged crankshaft key helps maintain proper pulley indexing and prevents assembly problems caused by worn or incorrectly fitting hardware.

Installation Notes

Before installation, inspect the crankshaft keyway and crankshaft pulley for damage, excessive wear, or debris.
Confirm that the replacement key matches the original component and is correct for your specific engine.
Clean the crankshaft keyway and carefully position the new Honda OEM key in its designated location.
Ensure that the key is properly seated before installing the crankshaft pulley.
Carefully align the crankshaft pulley keyway with the installed key and slide the pulley into position without forcing it.
Important: The crankshaft pulley key is an indexing component. Proper pulley retention depends on the crankshaft pulley bolt being installed and tightened according to Honda's factory service procedure.
Always follow the correct crankshaft pulley bolt torque specifications and installation requirements for your engine.
Do not install a crankshaft key that is bent, damaged, or excessively worn.
After installation, verify that the crankshaft pulley is properly seated and aligned before completing engine assembly.

Note:

Includes one genuine Honda OEM Crankshaft Pulley Key (4.5x21mm). Crankshaft pulleys, pulley bolts, timing components, and additional engine hardware are sold separately unless otherwise specified.

For Honda and Acura enthusiasts rebuilding a K-series engine, replacing a crankshaft pulley, or completing a performance engine project, this genuine Honda OEM Crankshaft Pulley Key provides factory-correct fitment and precise component alignment for dependable engine assembly.