Upper Gear Case Housing Seal & Gasket Kit – Fits Volvo Penta SX, DP-S, DP-SM Drives (Replaces 3850594)
Upper Gear Case Housing Seal & Gasket Kit – Fits Volvo Penta SX, DP-S, DP-SM Drives (Replaces 3850594) is backordered and will ship as soon as it is back in stock.
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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.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Upper Gear Case Housing Seal & Gasket Kit – Fits Volvo Penta SX...
Product Details
This Upper Gear Case Housing Seal & Gasket Kit is engineered for Volvo Penta SX, DP-S, and DP-SM stern drives manufactured from the mid-1990s through current models. It provides a comprehensive solution for servicing the upper gear housing on engines ranging from 4.3L to 8.2L.
It serves as a direct cross-reference for Volvo Penta 3850594, OMC 3850594, and GLM 87740, ensuring broad compatibility for repairs and maintenance.
- Designed for the upper gear housing/drive unit.
- Professional installation is recommended for optimal performance and safety.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 3850594 |
| OMC | 3850594 |
| GLM | 87740 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Volvo Penta applications, this kit covers SX, DP-S, and DP-SM drives across a wide range of engine sizes and gear ratios from the mid-1990s to the present.
For OMC applications, this kit is compatible with SX drives on various engine models manufactured between 1996 and 1998.
| Brand | Drive Model | Engine Size | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Volvo Penta | SX Drive | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | For upper gear housing |
| Volvo Penta | DP-S Drive | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | For upper gear housing |
| Volvo Penta | DP-SM Drive | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | For upper gear housing |
| Volvo Penta | DP-SM 1.68 | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | Specific gear ratio variant |
| Volvo Penta | DP-SM 1.78 | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | Specific gear ratio variant |
| Volvo Penta | DP-SM 1.95 | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | Specific gear ratio variant |
| Volvo Penta | DP-SM 2.32 | 4.3L-8.2L | 4-Stroke | Mid-1990s–Current | 3850594 | Specific gear ratio variant |
| OMC | SX | 4.3L | 4-Stroke | 1996–1998 | 3850594 | OMC/Volvo compatible |
| OMC | SX | 5.0L | 4-Stroke | 1996–1998 | 3850594 | OMC/Volvo compatible |
| OMC | SX | 5.7L | 4-Stroke | 1996–1998 | 3850594 | OMC/Volvo compatible |
| OMC | SX | 5.8L | 4-Stroke | 1996 | 3850594 | OMC/Volvo compatible |
| OMC | SX | 7.4L | 4-Stroke | 1996–1998 | 3850594 | OMC/Volvo compatible |
| OMC | SX | 8.2L | 4-Stroke | 1998 | 3850594 | OMC/Volvo compatible |
Technical Specs
- Product Type
- Upper Gear Case Housing Seal & Gasket Kit
- Installation
- Professional recommended
- Application
- For upper gear housing/drive unit
- Dimensions
- 9.5" L x 9.5" W x 6.0" H
What’s in the Box
- Seals (Multiple)
- Gaskets (Multiple)
- O-rings (Multiple)
Installation Notes
- Disconnect the battery and ensure the engine is off and cool.
- Drain the gear lube from the sterndrive unit.
- Following the manufacturer's service manual, remove the upper gear housing assembly.
- Carefully remove all old seals, gaskets, and O-rings, noting their position and orientation.
- Thoroughly clean all mating surfaces of old sealant, corrosion, and debris.
- Install the new components from the kit. Use appropriate seal drivers and sealant as specified in the service manual.
- Reassemble the gear housing, torquing all fasteners to the manufacturer’s specified values.
- Refill the sterndrive with the correct type and amount of fresh gear lube.
- After reassembly, check for any signs of oil or water leaks before and after operation.
Troubleshooting & FAQ
How do I confirm this kit fits my specific sterndrive?
This kit is designed for Volvo Penta SX, DP-S, and DP-SM drives. The most reliable method is to cross-reference your drive's OEM part number with 3850594. You can also consult the detailed compatibility tables on this page to verify by your drive model and year.
What are common signs that my upper gear housing seals are failing?
The most common symptom is water intrusion into the gear lube, which makes the oil appear milky white or gray. Other signs include visible oil leaks on the outside of the drive unit, a persistent low gear lube level, or unusual gear noise.
How often should these seals and gaskets be replaced?
There is no fixed replacement interval, but it is best practice to replace them whenever the drive unit is disassembled for other service. They should also be replaced immediately if any signs of leakage or water contamination are discovered during routine checks.
Is this an OEM or aftermarket part?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for quality and consistency.
What are the shipping speed and cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. See our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before ordering. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement part, not an OEM component.
- Professional installation is strongly recommended for safety, proper function, and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — Our parts deliver fair pricing without compromising on materials or quality control.
Payment & Security
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