Genuine Mazda Camshaft Timing Gear / Sprocket • LF01-12-425

Genuine Mazda LF01-12-425 Camshaft Timing Gear / Sprocket

Replacement Genuine Mazda camshaft timing gear for Mazda MX-5 Mk3, Mk3.5 and Mk3.75 / NC models with 1.8L and 2.0L petrol engines from 2005 to 2015 listed in the compatibility table.

This toothed camshaft gear—also described as a camshaft sprocket or timing-chain pulley—mounts to the end of the camshaft and is driven by the engine's primary timing chain. It transfers crankshaft rotation to the camshaft and helps maintain the correct relationship between piston movement and valve operation.

Accurate engagement between the timing chain and camshaft sprocket is essential for correct valve timing, stable engine operation, performance and emissions control.

The quantity required differs according to the engine. The 1.8L L8-DE engine uses two LF01-12-425 fixed camshaft gears. The 2.0L LF-VE engine uses one LF01-12-425 fixed camshaft gear, with the other camshaft fitted with a separate variable valve timing actuator.

This listing supplies one Genuine Mazda camshaft timing gear.

Replacement is normally considered during timing-chain repairs, cylinder-head work, camshaft replacement or a complete engine rebuild. The gear should also be replaced if inspection identifies worn or damaged teeth, abnormal timing-chain contact marks, damage to the mounting bore or locating surfaces, corrosion or distortion.

• Part type: Camshaft timing gear / camshaft sprocket / timing-chain pulley
• Primary use: Transfers timing-chain rotation to the camshaft
• Location: Cylinder head / camshaft timing-chain drive
• Engine applications: Mazda MX-5 NC 1.8L L8-DE and 2.0L LF-VE
• Drive type: Primary timing chain
• Quantity required – 1.8L L8-DE: Two per engine
• Quantity required – 2.0L LF-VE: One fixed gear per engine
• Quantity supplied: One camshaft gear
• Brand: Genuine Mazda
• Part No.: LF01-12-425
• Also referenced as: LF0112425
• Earlier or associated Mazda references: LF01-12-42Y, LF21-12-425 and 1F20-12-425
• Associated 2.0L component: Separate variable valve timing actuator on the other camshaft

Fitment advice: Confirm the engine type and the camshaft position being repaired before ordering. On the 1.8L engine, both camshafts use this fixed gear. On the 2.0L engine, only one camshaft uses this fixed gear because the other is equipped with a separate VVT actuator. Compare the original gear, timing marks and mounting arrangement before installation.

Other items to consider: When changing this part, you may also want to consider purchasing the timing chain, timing-chain guides, hydraulic chain tensioner, camshaft sprocket bolt and washer, crankshaft timing gear, front crankshaft oil seal, cam-cover gasket and the separate VVT actuator where applicable.

Useful tools / consumables: Mazda-compatible camshaft and crankshaft timing tools, camshaft holding tool, crankshaft pulley holding tool, socket set, breaker bar, calibrated torque wrench, engine assembly lubricant, gasket-surface cleaning equipment and the specified timing-cover sealant.

Difficulty guide: DIY Difficulty: Advanced. Installation requires substantial timing-system dismantling and accurate locking of the crankshaft and camshafts. Incorrect cam timing can cause poor running, fault codes or serious internal engine damage.

Why Genuine Mazda? Genuine Mazda camshaft gears are manufactured to the original tooth profile, mounting dimensions, runout, hardness and timing-mark specification. Using the correct OE component helps maintain accurate timing-chain engagement, camshaft phasing and compatibility with the original Mazda timing system.

What’s in the box: One Genuine Mazda camshaft timing gear / sprocket, part number LF01-12-425. The mounting bolt, timing chain, guides, tensioner and VVT actuator are not included.

Installation notes: Lock the crankshaft and camshafts in the correct timing position before dismantling the timing system. Inspect the timing chain, guides, tensioner and adjoining sprockets for wear. Fit the replacement gear in the correct orientation, align all timing references and tighten the mounting fastener to the applicable Mazda specification. Rotate the engine manually through at least two complete crankshaft revolutions and recheck the timing alignment before starting the engine.