Genuine Mazda Front Crankshaft Pulley Locking Bolt • LF01-11-406

Genuine Mazda LF01-11-406 Front Crankshaft Pulley Locking Bolt

Replacement Genuine Mazda front crankshaft pulley locking bolt for Mazda MX-5 Mk3, Mk3.5 and Mk3.75 NC models with 1.8 L8-VE or 2.0 LF-VE MZR petrol engines.

The bolt passes through the crankshaft pulley and its separate retaining washer before threading into the front of the crankshaft. It provides the clamping load required to retain the pulley securely against the crankshaft.

Correct clamping is essential for maintaining pulley security and the intended relationship between the crankshaft, timing components and ancillary-drive system. A stretched, damaged or incorrectly tightened bolt may not provide the required retaining force.

This fastener operates under substantial installation load and should be considered for replacement whenever the crankshaft pulley is removed, particularly during timing, crankshaft or complete engine-rebuild work.

One crankshaft pulley locking bolt is fitted per engine, and this listing supplies one Genuine Mazda bolt. The separate pulley washer, Mazda part number L3K9-11-407, is not included unless specifically stated in the supplied package.

• Part type: Front crankshaft pulley locking bolt
• Common names: Crank pulley bolt / crankshaft damper bolt
• Mazda catalogue description: Bolt, Lock – C.Shaft Pulley
• Location: Front end of the crankshaft
• Function: Secures the crankshaft pulley to the crankshaft
• Quantity fitted per engine: 1
• Quantity supplied: 1 bolt
• Crankshaft pulley included: No
• Pulley retaining washer included: No
• Separate washer reference: L3K9-11-407
• Brand: Genuine Mazda
• Part No.: LF01-11-406
• Earlier Mazda reference: 1F20-11-376
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC 1.8 and 2.0 models

Typical reasons for replacement:

• Crankshaft pulley removal or replacement
• Timing-chain or front engine-cover work
• Crankshaft inspection or replacement
• Complete engine rebuild
• Original bolt stretched or damaged
• Bolt head rounded during removal
• Thread damage or corrosion
• Incorrect previous tightening
• Pulley movement or loss of clamping force

Fitment advice: This bolt is intended for the original crankshaft and pulley arrangement fitted to Mazda MX-5 NC 1.8 L8 and 2.0 LF MZR engines. Confirm the fastener requirements where an alternative engine, aftermarket crankshaft pulley or modified timing assembly has been installed.

Other items to consider: Inspect the separate pulley washer, crankshaft pulley, crankshaft nose and threads, timing sprocket, crankshaft position components, auxiliary belt, tensioner and idler pulleys. Replace the washer if it is distorted, damaged or unsuitable for reuse.

Useful tools / consumables: Suitable crankshaft or flywheel holding tool, correctly sized socket, long breaker bar, calibrated torque wrench, angle gauge where required, thread-cleaning equipment and the applicable Mazda timing and alignment tools.

Difficulty guide: DIY Difficulty: Advanced. The crankshaft must be restrained using the correct method, and the engine timing must not be allowed to move unintentionally. The bolt must be tightened using the exact procedure specified for the applicable engine.

Why Genuine Mazda? Genuine Mazda crankshaft pulley bolts are manufactured to match the original crankshaft thread, bolt length, head profile, strength specification and tightening characteristics. Correct fastener dimensions help maintain the required pulley clamping load.

What’s in the box: One Genuine Mazda front crankshaft pulley locking bolt, part number LF01-11-406.

Installation notes: Follow the applicable Mazda workshop procedure before disturbing the crankshaft pulley. Position the engine and timing components as instructed and restrain the crankshaft using the specified holding method rather than relying on the timing drive. Remove the old bolt and inspect the crankshaft threads, pulley bore and separate retaining washer. Clean the mating surfaces and install the pulley and washer in their correct orientation. Start the new bolt by hand and tighten it using the prescribed torque sequence and any required angular stage. Confirm pulley alignment and engine timing before starting the engine.