Mercury MerCruiser Flywheel Retaining Screw 7/16-20 x 1.00 | 8M0214958
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Part Details
- Part Number: 8M0214958 (also listed as 10-8M0214958)
- Brand: Mercury Marine
- Product Type: Flywheel Retaining Screw
- Thread Size: 7/16-20 UNF (.437-20)
- Length: 1.00 in. (25.4 mm)
- Quantity Per Assembly: 6 screws per flywheel (verify against your parts diagram)
- GTIN / Barcode: 678633180644
- Supersedes: 845757 (10-845757) and 49845 (10-49845)
- System: Flywheel / crankshaft assembly
- Diagram Position: Flywheel-to-crankshaft retaining fasteners; also referenced in coupler assembly diagrams on applicable engines
Compatible Applications
Verify fitment using your engine serial number and the correct Mercury parts diagram before ordering. Documented applications associated with superseded numbers include:
- Mercury MerCruiser 120 / GM 153 I4
- Mercury MerCruiser 140 / GM 181 I4
- Mercury MerCruiser 165 / Mercury 224 I4
- Mercury MerCruiser 170 / Mercury 224 I4
- Mercury MerCruiser 180 / Mercury 224 I4
- Mercury MerCruiser 190 / Mercury 224 I4
- Mercury MerCruiser 2.5L GM I4
- Mercury MerCruiser 3.0L GM I4
8M0214958 also appears in later MerCruiser flywheel and coupler assemblies. Confirm by serial number and diagram — do not select by engine displacement alone.
Dimensions & Specifications
- Thread: 7/16-20 UNF (.437-20)
- Length: 1.00 in. (25.4 mm)
- Estimated weight: approx. 0.13 lb (0.059 kg) per screw
- Packed dimensions (estimated): 1.50 in. × 0.75 in. × 0.75 in. (3.81 cm × 1.91 cm × 1.91 cm)
Alternate & Superseded Part Numbers
- 8M0214958 / 10-8M0214958 — current active number
- 845757 / 10-845757 — superseded, replaced by 8M0214958
- 49845 / 10-49845 — earlier number, replaced by 8M0214958
When to Replace
Replace flywheel screws when they show damaged or stretched threads, rounded or damaged head surfaces, corrosion, deformation, or have been identified by Mercury service procedures as non-reusable after removal. Inspect all flywheel fasteners whenever the flywheel or engine coupler is removed during service.
Service Interval
Replace as required during any service procedure involving flywheel or coupler removal. Always consult the applicable Mercury MerCruiser service manual for torque specifications and fastener reuse guidelines.
Installation Notes
Ensure the crankshaft and flywheel mating surfaces are clean and correctly seated before installing screws. Use the tightening sequence and torque value specified in the Mercury MerCruiser service manual for the exact engine model and serial range. Do not substitute hardware-store fasteners based on diameter and length alone — the flywheel-to-crankshaft connection is torque-critical.
Parts Desk Insights
Flywheel screws are one of the most commonly under-ordered fasteners during engine service — customers frequently order for one screw rather than the full set of six. Check your parts diagram for the correct quantity before ordering. The most common question is whether 845757 and 49845 are still available; both have been superseded to 8M0214958, which is the current active Mercury part number for this fastener. Always verify against your engine serial number since MerCruiser used different flywheel and coupler configurations across engine generations.
Technical FAQ
Q: Are 845757 and 49845 still available?
A: Both have been superseded to 8M0214958, which is the current active Mercury part number.
Q: How many screws are needed per engine?
A: Mercury parts diagrams commonly specify 6 screws per flywheel assembly — confirm the exact quantity from your engine's flywheel diagram.
Q: What torque spec applies?
A: Refer to the Mercury MerCruiser service manual for the torque specification and tightening sequence for your specific engine model and serial range.
Q: Can I reuse the existing screws after removing the flywheel?
A: Inspect carefully for stretch, thread damage, or corrosion. Consult the Mercury service manual — some flywheel fasteners are designated as replacement-required after removal.
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.