Mercury MerCruiser Bravo III Front Propeller Nut 859131
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Mercury 859131 is a genuine OEM front propeller nut for Bravo III stern drives. Current Mercury dealer references show 859131 superseded to 8M0105210, and current Bravo III parts references identify it specifically as the front prop nut in the propeller hardware stack.
Key Features
- Genuine Mercury Marine OEM part number 859131.
- Current replacement part number is 8M0105210.
- Identified in current parts references as the front prop nut.
- Used on Bravo III propeller hardware, where it installs after the front propeller.
- Current dealer listing shows broad application coverage across Bravo One/Two/Three families, Bravo X, Bravo XR, Zeus 3000, and integrated/high-performance transom listings in Mercury's where-used records, but the clearest current product-level description is Bravo III front prop nut service.
Engine Compatibility
This is not an engine-only part. The strongest supportable fitment for 859131 is Bravo III sterndrive propeller hardware service, where current sources identify it as the front prop nut. Mercury's where-used records also show the superseded number across broader sterndrive and Zeus-family listings, so the safest fitment language is by drive model and propeller stack, not engine model alone.
Serial Number Fitment Notice
Verify fitment by exact drive model, serial number, and the correct propeller hardware diagram before ordering. With 859131, the important match is the front nut position in the Bravo III propeller stack, since Bravo III uses separate front and rear prop hardware.
When This Part Needs Replacement
Replace this prop nut when the original is damaged, corroded, rounded, distorted, or removed during propeller service and no longer suitable for reuse. Because it is part of the Bravo III propeller-retention hardware, correct fit and condition matter for secure propeller installation. This is a practical service inference supported by its documented front prop nut role.
Installation Notes
Install this part only after confirming the correct Bravo III propeller hardware order. Current Bravo III references show this as the front prop nut, which goes on after the front propeller and before the remaining Bravo III hardware stack.
Alternate/Superseded Part Numbers
Current Mercury references show 8M0105210 as the superseding replacement for 859131. Additional current cross-reference sources also associate older numbers 805092T and 805092 with this same Bravo III prop nut family.
Parts Desk Insight
With Bravo III prop hardware, the important match is the nut position in the prop stack. Confirming whether you need the front or rear nut first is the easiest way to avoid ordering the wrong prop hardware.
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Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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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.
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Important:
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