Genuine Mazda Front Crankshaft Oil Seal • L3G6-10-602

Genuine Mazda L3G6-10-602 Front Crankshaft Oil Seal

Replacement Genuine Mazda front crankshaft oil seal 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 seal is installed in the front timing-chain cover and runs against the crankshaft sealing surface behind the crankshaft pulley. Its flexible sealing lip retains engine oil while allowing the crankshaft to rotate.

Age, repeated heat cycles, crankshaft movement and long-term seal-lip wear can allow oil to escape from the front of the engine. Because the seal is concealed behind the crankshaft pulley, leakage may first appear around the lower timing cover, auxiliary belt or front oil-pan area.

One front crankshaft oil seal is fitted per engine, and this listing supplies one Genuine Mazda seal.

• Part type: Front crankshaft oil seal
• Common names: Front main seal / timing-cover crankshaft seal
• Mazda catalogue description: Seal, Oil
• Location: Front engine timing-chain cover
• Position relative to pulley: Behind the crankshaft pulley
• Function: Seals engine oil around the rotating front crankshaft
• Quantity fitted per engine: 1
• Quantity supplied: 1 oil seal
• Timing cover included: No
• Crankshaft pulley included: No
• Crankshaft pulley bolt included: No
• Diamond locking washers included: No
• Brand: Genuine Mazda
• Part No.: L3G6-10-602
• Associated Mazda references: LF01-10-602 / L507-10-602 / 1F20-10-602 / 1F20-10-602A / 8LGJ-10-271
• MX-5 fitment: Mk3, Mk3.5 and Mk3.75 NC 1.8 and 2.0 engines

Possible signs of a failing front crankshaft seal:

• Engine oil around the crankshaft pulley
• Oil residue on the lower timing cover
• Oil contamination of the auxiliary belt
• Oil collecting around the front of the oil pan
• Burning-oil smell where leaked oil reaches hot components
• Gradual engine-oil loss without an obvious upper-engine leak
• Visible hardening, cracking or damage after pulley removal

Fitment advice: This seal is intended for the original Mazda MX-5 NC 1.8 L8 and 2.0 LF MZR timing cover and crankshaft arrangement. Confirm compatibility where an alternative engine, replacement timing cover, aftermarket crankshaft pulley or modified timing system has been installed.

Diagnosis advice: Oil at the front of the engine may also originate from the timing-cover joints, camshaft cover, oil pan, timing-cover blind plugs or other nearby seals. Clean the area carefully before dismantling so the precise leak source can be identified.

Other items to consider: Inspect the crankshaft sealing surface, crankshaft pulley, centre bolt, diamond locking washers, timing sprocket, timing cover, auxiliary belt, belt tensioner and adjacent oil-pan sealing joints. A grooved or damaged crankshaft sealing surface may prevent a new seal from operating correctly.

Useful tools / consumables: Crankshaft holding tool, suitable pulley-removal equipment, correctly sized socket, breaker bar, calibrated torque wrench, angle gauge where required, seal puller, correctly sized seal-installation driver, suitable degreaser and lint-free cloths.

Difficulty guide: DIY Difficulty: Advanced. The crankshaft pulley must be removed and the replacement seal installed squarely without damaging its sealing lip or the timing-cover bore. The pulley and timing assembly must then be refitted using the correct Mazda procedure.

Why Genuine Mazda? Genuine Mazda crankshaft seals are manufactured to match the original timing-cover bore, crankshaft sealing diameter, seal depth and lip profile. Correct dimensions and sealing materials help provide reliable oil retention around the rotating crankshaft.

What’s in the box: One Genuine Mazda front crankshaft oil seal, part number L3G6-10-602.

Installation notes: Allow the engine to cool and follow the applicable Mazda workshop procedure before removing the auxiliary belt and crankshaft pulley. Secure the engine timing correctly and remove the old seal without scratching the crankshaft or aluminium timing-cover bore. Clean and inspect the crankshaft sealing surface and cover bore. Protect and lightly lubricate the new sealing lip only as directed by Mazda, then drive the seal in squarely to the specified depth using a correctly sized installer. Keep the crankshaft, timing-sprocket and locking-washer contact faces clean and dry during reassembly. Refit the pulley components and tighten the crankshaft bolt using the prescribed torque and angular stages. Check for oil leakage after the engine reaches operating temperature.