Mercury MerCruiser Quicksilver Crankshaft Oil Seal 66301
In stock items ship same or next day.
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You have 30 days to request a return. All sale items are final sale.
Product Description
Mercury 66301 is an oil seal used at crankshaft-bearing-housing and crankcase locations on specified Mercury outboards. On the illustrated Mercury 9.8 hp powerhead, the same number appears at the upper bearing housing and lower crankcase sealing positions.
Key Features
- Mercury catalog number: 26-66301
- Crankshaft oil seal
- Cataloged at upper bearing-housing and lower crankcase positions on the specified 9.8 hp assembly.
Engine Compatibility & Fitment Notice
Confirmed examples include Mercury 9.8 hp engines from USA serial 5206550 and Belgium serial 9217756 in the applicable cylinder-block and crankcase diagram. Verify the exact sealing position and engine serial number before ordering. Check the shaft sealing surface and bearing housing during replacement; install to the specified depth and orientation.
Alternate / Superseded Part Numbers
26-66301 supersedes earlier seal 26-56741.
When This Part Needs Replacement
Replace a damaged oil seal or one implicated in leakage at the specified crankshaft sealing position.
Installation Notes
Protect the seal lip while fitting it over the shaft and follow the engine procedure for orientation and seating depth.
Mercury Parts Finder
Search Mercury parts by serial number or part number.
Parts Desk Insight
On the specified 9.8 hp powerhead, this seal number appears at both ends of the crankshaft; order by the number of positions being serviced.
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.