Mercury MerCruiser Quicksilver — 5/16-18 × 1-1/4 in. Screw — 74824
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Mercury MerCruiser Quicksilver 5/16-18 × 1-1/4 in. Screw 74824
Mercury MerCruiser Quicksilver 74824 is a genuine OEM 5/16-18 × 1.250 in. screw used in multiple Mercury Marine engine assemblies. Documented locations include alternator braces, cylinder-block and crankcase assemblies, cooling-system components, and thermostat or reservoir assemblies.
Compatible Applications
- Select Mercury and Mariner outboards
- Select Mercury V6 outboard cylinder-block and crankcase assemblies
- Mercury 240 EFI M2 Jet Drive cylinder-block applications
- MerCruiser 470 and 3.7L cooling-system and thermostat-reservoir assemblies
- Select MerCruiser alternator-brace assemblies
- Additional Mercury and MerCruiser assemblies whose OEM diagram specifies 74824
Fitment notice: This is a multi-application fastener. Confirm the engine or drive serial number, OEM diagram position, required quantity, and associated washers, spacers, or locking hardware before ordering.
Part Details
- Current part number: 74824
- Mercury reference: 10-74824
- Brand: Mercury MerCruiser Quicksilver
- Product type: Engine assembly screw
- Thread: 5/16-18 UNC
- Thread diameter: 0.3125 in. or 5/16 in.
- Length: 1.250 in. or 31.75 mm
- GTIN: 745061076617
- Sold as: One screw
- Earlier reference: 53016 in select MerCruiser 470 cooling-system applications
- Condition: New
Key Features
- Genuine OEM fastener
- Used across multiple outboard and MerCruiser engine assemblies
- Diagram-specific hardware for alternator, crankcase, cooling, and thermostat applications
- Sold individually for service replacement
When to Replace This Screw
Replace the screw if its threads are damaged, stretched, or stripped; the head is rounded; significant corrosion is present; the original fastener was lost; or the service procedure specifies new hardware. Do not reuse a screw that can no longer be tightened correctly.
Installation Notes
Confirm that 74824 is specified for the exact diagram position. Use the associated OEM washer, lock washer, or spacer where shown. Tightening torque, locking compound, and reuse limits should follow the service procedure for the particular engine assembly rather than being inferred from screw size alone.
Technical FAQ
Is this screw limited to one engine family?
No. It appears in several unrelated Mercury and MerCruiser engine assemblies.
Do the dimensions alone confirm fitment?
No. Match part number 74824 to the serial-specific diagram and exact assembly position.
Are washers or spacers included?
This listing is for one screw. Check the OEM diagram for any separate washer, lock washer, or spacer required at the installation point.
Parts Desk Insights
Best use case: Replacing a missing or damaged fastener when the exact engine diagram specifies Mercury part 74824.
Most common mistake: Ordering by 5/16-18 × 1-1/4 in. dimensions alone and overlooking diagram-specific washers, spacers, quantity, or tightening requirements.
Fitment guidance: Confirm the engine serial number, diagram position, quantity, and associated hardware before installation, especially on alternator-brace and cylinder-block applications.
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.