Mercury MerCruiser Quicksilver — 5/8-18 Hex Nut — 8M0214915
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Mercury MerCruiser Quicksilver 5/8-18 Hex Nut 8M0214915
Mercury MerCruiser Quicksilver 8M0214915 is a genuine OEM 5/8-18 hex nut used in multiple Mercury Marine engine and drive assemblies. Depending on the application, it may serve as a flywheel retaining nut, a drive-gear-to-universal-joint nut, or another assembly-specific retaining fastener.
Compatible Applications
- Select Mercury and Mariner outboards where the OEM diagram specifies this flywheel nut
- Select legacy Mercury 850 six-cylinder outboard applications
- Select MerCruiser sterndrives where the OEM diagram specifies this drive-gear-to-universal-joint nut
- Select R and MR drive applications
- Select Alpha One and Alpha One Gen II drive applications
- Select Bravo drive applications
Fitment notice: This is a multi-application fastener. Confirm fitment using the engine or drive serial number and the applicable Mercury parts diagram. Do not select it by appearance or thread size alone.
Part Details
- Current OEM part number: 8M0214915
- Mercury prefix reference: 11-8M0214915
- Brand: Mercury MerCruiser Quicksilver
- Product type: Hex retaining nut
- Thread: 5/8-18 UNF
- Condition: New
Alternate and Superseded Part Numbers
- 22339
- 97522
- 36084
- F1348
- F1881
- F1920
Mercury parts diagrams identify 22339 and 97522 as superseded by 8M0214915. The other numbers are legacy cross-references associated with the current nut.
Key Features
- Genuine OEM retaining fastener
- 5/8-18 UNF thread
- Used in multiple engine and sterndrive assemblies
- Current replacement for several earlier OEM nut numbers
When to Replace This Nut
Replace the nut if its threads are damaged, stretched, stripped, or corroded; the hex flats are rounded; the original fastener has been lost; or the applicable service procedure requires a new retaining fastener during flywheel, drive-gear, or related major-component service.
Installation Notes
Confirm the installation location before fitting the nut. Follow the Mercury or MerCruiser service procedure for the exact engine or drive to determine the required washer or related hardware, thread preparation, tightening torque, and any locking or replacement requirements. Do not substitute a generic 5/8-18 nut solely because the thread size matches.
Technical FAQ
Is this nut used only on outboards?
No. It appears in both select outboard flywheel applications and select MerCruiser sterndrive assemblies.
Does the 5/8-18 thread confirm compatibility?
No. Mercury used different retaining hardware across similar assemblies. Match the complete part number to the serial-specific diagram.
Is a tightening torque included?
No universal torque is listed because this nut is used in multiple assemblies. Use the service procedure for the exact installation.
Parts Desk Insights
Best use case: Replacing the specified retaining nut during flywheel, drive-gear, universal-joint, or related assembly service when the OEM diagram calls for 8M0214915.
Most common mistake: Treating thread size as proof of fitment. A generic 5/8-18 nut may not meet the installation requirements for a critical rotating assembly.
Fitment guidance: Match 8M0214915 to the exact engine or drive serial number, diagram position, washer arrangement, and service procedure before installation.
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
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.