Genuine Mazda Crankshaft Timing Sprocket Diamond Locking Washer • L3K9-11-407

Genuine Mazda L3K9-11-407 Crankshaft Timing Sprocket Diamond Locking Washer

Replacement Genuine Mazda crankshaft timing-sprocket diamond locking washer 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 MZR engine uses two high-friction locking washers within the front crankshaft and timing assembly. One washer is installed on each side of the crankshaft timing-chain sprocket.

When the crankshaft pulley centre bolt is tightened correctly, the washers create high-friction interfaces between the crankshaft, timing sprocket and pulley assembly. This clamping arrangement prevents the timing sprocket moving independently of the crankshaft and helps maintain accurate valve timing.

This engine design does not rely solely on a conventional locating key to retain the crankshaft timing sprocket. The condition, position and cleanliness of both locking washers, together with the correct centre-bolt tightening procedure, are therefore critical.

Two diamond locking washers are fitted per engine. This listing supplies one Genuine Mazda washer, so select a quantity of two when replacing the complete set.

• Part type: Crankshaft timing-sprocket locking washer
• Common names: Diamond washer / friction washer / crankshaft sprocket washer
• Mazda catalogue description: Washer, Lock
• Location: Front crankshaft timing-chain sprocket assembly
• Installation arrangement: One washer on either side of the timing sprocket
• Function: Provides a high-friction clamping interface within the crankshaft timing assembly
• Quantity fitted per engine: 2
• Quantity supplied: 1 washer
• Timing-chain sprocket included: No
• Crankshaft pulley included: No
• Crankshaft pulley centre bolt included: No
• Centre bolt reference: LF01-11-406
• Brand: Genuine Mazda
• Part No.: L3K9-11-407
• Associated Mazda references: L3H5-11-407 / 1F20-11-407
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC 1.8 and 2.0 engines

Typical reasons for replacement:

• Timing-chain or front engine-cover work
• Crankshaft pulley or timing sprocket removal
• Crankshaft replacement
• Complete engine rebuild
• Original washer damaged or contaminated
• Friction coating worn, marked or flattened
• Previous timing-sprocket movement or timing slip
• Incorrect assembly discovered during engine dismantling

Important quantity note: Two washers are required per engine. One sits between the crankshaft shoulder and timing sprocket, while the second sits between the timing sprocket and the adjacent pulley or retaining assembly. This listing supplies one washer only.

Fitment advice: This washer is intended for the original Mazda MX-5 NC 1.8 L8 and 2.0 LF MZR crankshaft and timing arrangement. Confirm the required components where an alternative engine, aftermarket timing gear, keyed crankshaft conversion or modified pulley assembly has been installed.

Other items to consider: Inspect and consider replacing both locking washers, the crankshaft pulley centre bolt, separate bolt washer where applicable, timing-chain sprocket, timing chain, guides, tensioner, crankshaft pulley and front crankshaft oil seal.

Useful tools / consumables: Mazda-compatible crankshaft and camshaft timing tools, crankshaft holding tool, correctly sized socket, long breaker bar, calibrated torque wrench, angle gauge, suitable degreaser and lint-free cloths.

Difficulty guide: DIY Difficulty: Specialist / Advanced. Incorrect installation can allow the crankshaft sprocket to slip and alter valve timing. Precise timing-tool setup, surface preparation and centre-bolt tightening are essential.

Why Genuine Mazda? Genuine Mazda locking washers are manufactured with the correct thickness, surface finish and friction coating for the original MZR crankshaft timing assembly. Correct friction characteristics are essential for achieving the designed resistance to sprocket movement.

What’s in the box: One Genuine Mazda crankshaft timing-sprocket diamond locking washer, part number L3K9-11-407.

Installation notes: Set and secure the engine timing using the applicable Mazda workshop procedure before loosening the crankshaft pulley centre bolt. Remove the pulley and timing components without allowing the crankshaft or camshafts to move independently. Identify the position of both locking washers and discard any washer that is damaged, contaminated or unsuitable for reuse. Clean the crankshaft, sprocket and pulley contact faces thoroughly so they are dry and free from oil, assembly lubricant and debris. Install one locking washer on each side of the crankshaft timing sprocket in the specified arrangement. Refit the remaining components and tighten the crankshaft pulley bolt using the prescribed torque and angular stages while the crankshaft is restrained with the correct tool. Reconfirm camshaft and crankshaft timing before rotating or starting the engine.