Mercury Propeller Wrench 13/16" 859046M2 – OEM Service Tool
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Mercury Propeller Wrench 13/16" – 859046M2
Part Number: 859046M2 (Mercury catalog prefix: 91-859046M2)
Brand: Mercury Marine (Quicksilver OEM)
Official Product Type: Propeller Wrench / Service Tool
Drive Size: 13/16"
System: Propeller Removal & Installation
Condition: New OEM
What It Does
The Mercury 859046M2 is a genuine OEM service tool — a 13/16" propeller wrench purpose-built for removing and installing propeller nuts on selected Mercury outboard and MerCruiser sterndrive applications. The 91- prefix in Mercury’s catalog system designates this as a service tool, not a replacement part. Using the correct OEM wrench ensures proper fit on the propeller nut without rounding the flats, and is particularly important on applications where access is tight or where the nut design requires a specific socket profile.
Compatible Applications
- Selected Mercury outboard engines requiring a 13/16" propeller nut wrench — verify by model and service manual
- Selected MerCruiser sterndrive applications — verify by model and service manual
Note: This is a service tool, not an engine-specific replacement part. Compatibility is determined by the propeller nut size on your engine, not by serial number. Confirm the correct wrench size for your application in the Mercury service manual or parts diagram before ordering.
Dimensions
Wrench Size: 13/16" (fits 13/16" propeller nut flats)
Part Revision: M2 suffix indicates current production revision
Supersedes / Alternate Part Numbers
- 859046M2 — current Mercury OEM part number
- 91-859046M2 — full catalog format with service tool prefix
Kit Contents
Single OEM propeller wrench. No additional components included.
Service Interval
This is a service tool — it does not have a replacement interval. Replace if the wrench is cracked, the drive is worn, or the socket no longer fits the nut flats squarely. A worn wrench that slips on the nut can round the nut flats and make future removal significantly more difficult.
Technical FAQ
Q: Why do I need a specific Mercury propeller wrench instead of a standard 13/16" socket?
In many cases a standard 13/16" socket will work, but Mercury’s OEM wrench is designed for the specific depth, clearance, and profile of their propeller nut. On some applications, the hub or thrust washer limits access and requires a purpose-built tool to seat properly without damaging surrounding components.
Q: What size propeller nut does this wrench fit?
This wrench is sized for 13/16" propeller nut flats. If your propeller nut is a different size, you will need a different wrench. Common Mercury propeller nut sizes include 13/16" and 1-1/16" — check your service manual to confirm the correct size for your engine.
Q: Can I use an impact wrench with this tool?
Mercury service manuals generally specify hand-torque with a torque wrench for propeller nut installation — not an impact driver. Using an impact wrench risks over-torquing the nut or damaging the propeller shaft threads. Always follow the torque specification in your service manual.
Related Products
- Mercury Propeller Shaft Nut 858869 – 7/8"-14 UNF OEM
- Mercury Propeller Nut Kit 8M0056235
- Mercury MerCruiser Quicksilver Propeller Nut Kit 69578Q1
- Mercury Quicksilver Propeller Nut Kit 11-52707Q1
- Mercury Quicksilver Flo-Torq II Hub Kit 835257K6
- Mercury Quicksilver Flo-Torq II Hub Kit 835257K1
Parts Desk Insights
Best Use Case: This wrench is the right call for shops or serious DIY owners who regularly service Mercury outboards and want the correct OEM tool on hand. It’s especially useful when working on engines where hub clearance is tight and a standard deep socket won’t seat properly. If you’re doing a one-time propeller swap and have a standard 13/16" socket that fits cleanly, you may not need this tool — but for repeated service work, having the right wrench prevents rounded nuts and frustration.
Common Mistakes: The most common mistake is using an adjustable wrench or the wrong size socket on a propeller nut. This rounds the nut flats quickly, especially on aluminum nuts that have been exposed to saltwater. Once the flats are rounded, removal becomes a much bigger job. A second common error is using an impact wrench for installation — propeller nuts have a specific torque value and must be hand-torqued with a torque wrench to avoid shaft thread damage.
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.