Mercury MerCruiser Quicksilver 5/8-18 Flywheel Nut 8M0214915
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Part Details
- Part Number: 8M0214915
- Service Format: 11-8M0214915
- Brand: Mercury / Quicksilver
- Type: Flywheel retaining nut — 5/8”-18 thread
- System: Engine — flywheel assembly / crankshaft retaining hardware
- Diagram Position: Flywheel assembly — secures flywheel to crankshaft, used with flywheel washer and crankshaft key
- Qty Per Assembly: 1
- GTIN: 678633180217
- Replaces: 22339 (primary supersession); also supersedes 97522, 36084, F1348
- Weight: Approx. 0.01 kg
About This Part
Genuine Mercury / Quicksilver 11-8M0214915 is the current OEM 5/8”-18 flywheel retaining nut for selected Mercury outboard and MerCruiser engine assemblies. Mercury parts diagrams identify it as the flywheel nut, installed with the corresponding flywheel washer and crankshaft key to secure the flywheel to the crankshaft. It is the current replacement for earlier flywheel nut 22339, and also supersedes 97522, 36084, and F1348 across various legacy Mercury and MerCruiser applications. Because 8M0214915 appears across numerous engine families as a shared hardware number, exact fitment should always be confirmed by engine model, serial number, and the exploded-view flywheel diagram position.
Compatible Applications
- Selected Mercury outboard engines — flywheel assembly (confirm by serial number and flywheel diagram)
- Selected MerCruiser inboard and sterndrive engines — flywheel retaining hardware (confirm by serial number)
- Legacy Mercury and MerCruiser assemblies previously listing flywheel nut 22339, 97522, 36084, or F1348
Confirm compatibility by engine model, serial number, and the flywheel assembly diagram. Mercury diagrams pair 8M0214915 with different flywheel washers depending on engine family, including 33001, 65891, 36258, and 36281 — confirm the complete hardware set from the diagram for your specific engine.
When to Replace
Replace this flywheel nut if it shows any of the following:
- Damaged, distorted, or cross-threaded engagement on the crankshaft
- Rounded hex flats from incorrect tool use
- Severe corrosion affecting thread integrity
- Evidence of overtightening or fatigue
- Poor thread engagement on reassembly
- The applicable Mercury service procedure specifies new retaining hardware after removal
Installation Notes
Before installation, inspect the crankshaft threads, flywheel washer, and flywheel key. Confirm which flywheel washer is specified for your engine from the parts diagram — Mercury uses different washers (33001, 65891, 36258, 36281) with this nut across different engine families. Torque 8M0214915 to the flywheel-nut specification in the Mercury service manual for your exact engine model — do not apply a generic 5/8”-18 torque value, as flywheel retaining torque is a critical specification that varies by engine family.
Cross-Reference Part Numbers
- Current OEM: 8M0214915 / 11-8M0214915
- Replaces (primary): 22339
- Also supersedes: 97522, 36084, F1348
- GTIN: 678633180217
- Used with (flywheel washers, varies by engine): 33001, 65891, 36258, 36281
Parts Desk Insight
8M0214915 is Mercury’s current 5/8”-18 flywheel nut, and its most important application is securing the flywheel to the crankshaft — a torque-critical location where using the correct OEM part and service manual torque specification matters. The most common mistake is applying a generic torque value based on thread size rather than the engine-specific flywheel torque spec, which can lead to a loose or damaged flywheel over time. When replacing this nut, always inspect the flywheel washer and crankshaft key at the same service visit, as these components are part of the same assembly and are inexpensive insurance against a repeat repair.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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