Volvo Penta Shaft O-Ring 3852565 | SX DPS Forward Drive OEM Seal
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Volvo Penta Shaft O-Ring — Part #3852565
An OEM-spec sealing ring for the U-joint shaft, bearing carrier, and related drive shaft locations on compatible Volvo Penta sterndrive assemblies. This O-ring prevents water intrusion and lubricant loss at the shaft seal interface — a small part that protects expensive drive components from corrosion and premature wear.
Part Details
- Part Number: 3852565
- Supersedes: Volvo Penta 997368
- Brand: Volvo Penta OEM
- Official Product Type: Shaft O-Ring
- System: Sterndrive Shaft & Bearing Carrier Sealing System
- Dimensions: ID 0.862" (21.9 mm) × Thickness 0.103" (2.6 mm)
- Sold: Individually
Compatible Applications
- Volvo Penta SX sterndrive
- Volvo Penta SX-M sterndrive
- Volvo Penta DPS-A sterndrive
- Volvo Penta DPS-B sterndrive
- Volvo Penta DPS-B1 sterndrive
- Volvo Penta Forward Drive
- Select OMC Cobra SX joint-era drive applications (cross-reference)
- Verify fitment by drive serial number, transom shield diagram, and original O-ring part number before ordering — O-ring dimensions and groove specifications vary between drive generations
Cross-Reference / Alternate Part Numbers
- Volvo Penta (superseded): 997368
- Mercury / MerCruiser: 25-25439, 25-20679
- OMC: 0911851
- Chrysler / Force: F53795-1
- Sierra Marine: 18-7153
- GLM Marine: 81180
Related Parts & Service Items
- Volvo Penta Seal 3852272
- Volvo Penta Propeller Shaft Oil Seal 3863090
- Volvo Penta Lower Gear Housing O-Ring SX-A DPS 3889786
- Volvo Penta Exhaust Bellows Kit 3888916
- U-Joint Bellows
Service Interval
Replace this O-ring any time the U-joint shaft, bearing carrier, or drive assembly is disassembled for service. Also replace immediately if the O-ring shows flattening, cracking, swelling, hardening, cuts, or is missing entirely. Do not reuse a compressed O-ring — it will not seal reliably on reassembly.
Technical FAQ
Q: How do I confirm this is the correct O-ring for my drive?
A: Cross-reference part number 3852565 or the superseded number 997368 against the Volvo Penta parts diagram for your specific drive model and serial number. You can also match by the O-ring dimensions: ID 21.9 mm, thickness 2.6 mm.
Q: Can I use a generic O-ring of the same size?
A: Marine drive O-rings are exposed to gear oil, water, and heat cycling. OEM or marine-grade nitrile O-rings are recommended — generic hardware-store O-rings may not hold up in this environment.
Q: What lubricant should I use when installing this O-ring?
A: Use a Volvo Penta-approved assembly lubricant or clean gear oil. Avoid petroleum-based greases that can degrade rubber compounds. Refer to your drive service manual for the recommended lubricant for this location.
Parts Desk Insights
Best use case: This O-ring is most commonly ordered as part of a U-joint shaft service, bearing carrier rebuild, or full drive reseal. If the drive is already apart, replacing this O-ring at the same time is a low-cost step that prevents having to revisit the job if the old seal weeps later.
Common issues we see: Customers sometimes order by the superseded number 997368 and aren’t sure if 3852565 is the correct replacement — it is. We also see fitment questions from owners of OMC Cobra SX-era drives, which share this O-ring in certain shaft locations. When in doubt, match by the dimensions (ID 21.9 mm × 2.6 mm thick) and confirm against your drive diagram.
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
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.