• Free shipping

  • Free help & advice

  • Hassle-free returns

  • Factory direct prices

Flash Sale now on!

FLASHSALE25

Lower Unit Gasket Seal Kit – Fits Volvo Penta, OMC 4.3-8.2L (Replaces 3856002, 0769577)

Regular price $65.99
Shipping calculated at checkout.

Lower Unit Gasket Seal Kit – Fits Volvo Penta, OMC 4.3-8.2L (Replaces 3856002, 0769577) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This is a complete Lower Unit Gasket Seal Kit for Volvo Penta DP-S, DP-SM, and DP-SMTD series sterndrives (1996–1998) and OMC 4.3L to 8.2L V6 & V8 sterndrive engines (1996–1998). It provides all necessary seals and O-rings for servicing the lower unit, specifically in Duo-Prop applications, ensuring a precise fit and reliable performance.

This kit directly replaces Volvo Penta part number 3856002 and OMC part numbers 3856002 and 0769577, providing a comprehensive solution for lower unit maintenance and resealing.

  • Engineered for direct replacement of OEM components.
  • Specifically designed for gasoline sterndrive engines.
  • Includes all essential seals and gaskets for a lower unit service.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number
Volvo Penta 3856002
OMC 3856002
OMC 0769577

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This kit fits Volvo Penta DP-S, DP-S1, DP-SM, DP-SMTD, and various SX models from 1996–1998.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Volvo Penta DP-S 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-S1 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SM 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SM 1.68 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SM 1.78 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SM 1.95 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SM 2.32 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SMTD 1.95 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SMTD1 1.95 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta DP-SMTD3 2.11 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta SX-C, SX-C1, SX-C2 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta SX-C1AC, SX-C2AC 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta SX-CLT, SX-CLT1 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta SX-CT, SX-CT1 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta SX-R, SX-RT1, SX-RT2 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application
Volvo Penta SX-R1, SX-R2 4-Stroke 1996–1998 3856002 Lower Unit Duo Prop Application

Also compatible with OMC V6 and V8 sterndrive engines from 1996–1998.

Brand Model Rated HP Stroke Years OEM Part No. Notes
OMC 4.3L 4.3L 4-Stroke 1996–1998 0769577 V6 Sterndrive
OMC 5.0L 5.0L 4-Stroke 1996, 1998 0769577 V8 Sterndrive
OMC 5.7L 5.7L 4-Stroke 1996–1998 0769577 V8 Sterndrive
OMC 5.8L 5.8L 4-Stroke 1996 0769577 V8 Sterndrive
OMC 7.4L 7.4L 4-Stroke 1996–1998 0769577 V8 Sterndrive
OMC 8.2L 8.2L 4-Stroke 1998 0769577 V8 Sterndrive

Technical Specs

Product Type
Lower Unit Gasket & Seal Kit
Installation
Direct replacement
Fuel Type
Gasoline
Warranty
Varies by manufacturer (OEM 1-year typical, aftermarket varies)
Other Technical Attributes
Specifically designed for Duo-Prop applications

What’s in the Box

  • 2 x Sealing Rings (Replaces 851407, 18-0558)
  • 2 x Sealing Rings (Replaces 853807, 18-2100)
  • 2 x Sealing Rings (Replaces 853808)
  • 2 x O-Rings (Replaces 946438)
  • 1 x O-Ring (Replaces 955981)
  • 1 x O-Ring (Replaces 3852866)
  • 1 x O-Ring (Replaces 3852959)
  • 1 x O-Ring (Replaces 3854624)
  • 2 x O-Rings (Replaces 3854625)
  • 1 x Water Tube Seal (Replaces 3852315, 18-32882)
  • 1 x Seal (Replaces 3854595)

Installation Notes

  1. Drain the gear lube from the lower unit completely.
  2. Disconnect any speedometer tubes and shift linkages attached to the lower unit.
  3. Remove the mounting bolts securing the lower unit to the upper housing. Carefully lower and remove the unit.
  4. Disassemble the lower unit as required to access the seals and gaskets being replaced. Keep parts organized.
  5. Thoroughly clean all mating surfaces, removing any old gasket material or sealant residue.
  6. Install the new seals, O-rings, and gaskets from the kit. Ensure seals are properly seated and lubricate them lightly with marine grease.
  7. Reassemble the lower unit components according to the manufacturer's service manual specifications.
  8. Reinstall the lower unit to the upper housing, ensuring the driveshaft, shift shaft, and water tube align correctly.
  9. Torque all bolts to the specified values. Reconnect linkages and tubes.
  10. Refill the lower unit with the correct type and amount of gear lube. Check for leaks before operation.

Troubleshooting & FAQ

How do I know if this gasket kit will fit my engine?

This kit is designed for specific Volvo Penta and OMC sterndrive models from 1996 to 1998. Please check the "Engine & Model Compatibility" and "Part Number Matrix" sections carefully. Comparing the OEM part number from your service manual to our listed cross-references (3856002, 0769577) is the most reliable way to confirm fitment.

What are the signs my lower unit needs new seals?

Common symptoms include milky or water-contaminated gear lube (indicating a water leak), visible oil leaking from the lower unit, or a persistent smell of gear oil around the drive. A pressure and vacuum test of the gearcase is the definitive way to diagnose leaking seals.

Is this kit for a complete lower unit rebuild?

This kit contains the essential gaskets, seals, and O-rings needed for a standard reseal or service of the lower unit. It does not include bearings, gears, or other hard parts. It is intended to stop leaks and restore the integrity of the gearcase seals.

How often should lower unit seals be replaced?

There is no fixed interval, but it is good practice to inspect your gear lube annually. Seals should be replaced whenever you find water intrusion, if the drive is being disassembled for other service, or as part of a major overhaul (typically every 5-10 years depending on use and conditions).

Are any special tools required for installation?

Yes, installation requires standard mechanic's tools as well as a gearcase pressure/vacuum tester to check for leaks after assembly. Depending on the specific drive model, you may also need a seal puller, seal driver, and a service manual for torque specifications and procedures.

Is there a difference in quality between OEM and this aftermarket kit?

This listing is an aftermarket replacement (not OEM). It's built to meet or exceed OEM-level specifications with comparable, high-quality materials. Our parts are manufactured in an ISO 9002 certified facility and are batch-inspected to ensure consistency and reliability.

What is your shipping speed and cost?

We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free for most orders, and expedited options will appear at checkout if they are available for your location.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window, provided the item is unused and in its original condition. Please see our policy page or reach out for instructions.

Safety & Important Info

  • Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement part, not an original equipment (OEM) component.
  • Professional installation by a qualified marine mechanic is highly recommended for safety and optimal performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world saltwater and freshwater conditions.
  • Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of just 5–15 days from our manufacturer-direct supply chain.
  • Manufacturer-Direct Value — By eliminating middlemen, we provide fair, direct pricing without ever compromising on materials or quality control.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • JCB
  • Maestro
  • Mastercard
  • PayPal
  • Union Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.