O-Ring Kit – Fits Volvo Penta SX/DPS Series (Replaces 3855081, 3852045)
O-Ring Kit – Fits Volvo Penta SX/DPS Series (Replaces 3855081, 3852045) is backordered and will ship as soon as it is back in stock.
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O-Ring Kit – Fits Volvo Penta SX/DPS Series (Replaces 3855081, 3852...
Product Details
This replacement O-Ring Kit – Fits Volvo Penta SX/DPS Series Outdrives (Replaces 3855081, 3852045) is designed for a precise fit on Volvo Penta SX-M, SX-A, DPS-A, and DPS-B series sterndrives. The kit provides the necessary seals for the oil drainage, ventilation, and dipstick systems, ensuring a leak-free seal to protect your drive's internal components.
It serves as a direct interchange for multiple OEM and aftermarket part numbers, including Volvo Penta 3855081 and 3852045; Sierra 18-7116 and 18-7145; GLM 81100; Johnson/Evinrude 303067, 329381, and 332584; and Mercury/Mariner 25-20633 and 25-22174.
- Engineered as a direct fit replacement for easy installation.
- Specifically designed for sealing the oil drainage and ventilation systems.
- Includes all O-rings required for a complete dipstick, vent, and drain plug service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 3855081 |
| Volvo Penta | 3852045 |
| Sierra | 18-7116 |
| Sierra | 18-7145 |
| GLM | 81100 |
| Johnson/Evinrude | 303067 / 0303067 |
| Johnson/Evinrude | 329381 / 0329381 |
| Johnson/Evinrude | 332584 / 0332584 |
| Mercury/Mariner | 25-20633 |
| Mercury/Mariner | 25-22174 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Volvo Penta drives, this kit fits a wide range of SX, DPS, and DPX series models. Please verify your specific model and ratio.
For Mercury, OMC, Johnson, and Evinrude applications, these O-rings are used in various gearcase assemblies. Check your service manual for the exact part number.
| Brand | Model | Ratio | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Volvo Penta | SX-A | 1.43, 1.51, 1.60, 1.66 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | SX-A | 1.79, 1.89, 1.97, 2.18 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | DPS-A | 1.68, 1.78, 1.95 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | DPS-A | 2.11, 2.14, 2.32 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | DPS-B | 1.78, 1.95, 2.14, 2.32 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | SX-M | 1.43, 1.51, 1.60, 1.66 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | SX-M | 1.79, 1.89, 1.97, 2.18 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | SX-MTD | 1.66, 1.79 | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | SX-C, SX-C1, SX-C2 | Various | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | SX-R, SX-RT1, SX-RT2, SX-S, SX-ST | Various | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | DP-G, DP-S1, DP-SM | Various | 4-Stroke | 3852045, 3855081 | Including ratio models 1.68, 1.78, 1.95, 2.32 |
| Volvo Penta | DP-SMTD, DP-SMTD1, DP-SMTD3 | Various | 4-Stroke | 3852045, 3855081 | Including ratio models 1.95, 2.11 |
| Volvo Penta | DPX-A | Various | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | X-B, X-BLT, XDP-B, XHP-B, XHP-BLT | Various | 4-Stroke | 3852045, 3855081 | |
| Volvo Penta | XXP-A, XXP-ALT, XXP-D3 | Various | 4-Stroke | 3852045, 3855081 |
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Mercury/Mariner | Various | 3.9 - 75 HP | 2-Stroke & 4-Stroke | 25-20633, 25-22174, 25-62704, 25-85148, 802206 | For gearcase assembly parts |
| Johnson/Evinrude | Loopcharged Models | 40-60 HP | 2-Stroke | 303067/0303067, 329381/0329381, 332584/0332584 | 2-cylinder engines |
| Johnson/Evinrude | Loopcharged Models | 60-75 HP | 2-Stroke | 303067/0303067, 329381/0329381, 332584/0332584 | 3-cylinder engines |
| OMC | Cobra | N/A | N/A | 303067, 3852045 | Upper gear case |
Technical Specs
- Product Type
- Lower Unit O-Ring Seal Kit
- Installation
- Direct fit replacement
- Housing Material
- Rubber
- Housing Color
- Black
- Dimensions
- Dipstick O-Ring: 6.35mm ID × 2.54mm width (0.250" × 0.100")
- Weight
- 0.10 kg (0.22 lb)
- Fitting Type
- O-Ring seals
- Other Technical Attributes
- Designed for oil drainage and ventilation system sealing
What’s in the Box
- 1 x Dipstick O-Ring (Replaces 3852045)
- 1 x Vent O-Ring (Replaces 3855081)
- 1 x Drain O-Ring (Replaces 3855081)
Installation Notes
- Position a drain pan under the outdrive's lower drain screw.
- Remove the lower drain screw and the upper vent screw (or dipstick) to allow the oil to drain completely.
- Carefully remove the old, compressed O-rings from the drain screw, vent screw, and dipstick. Clean the plug threads and sealing surfaces.
- Lightly lubricate the new O-rings from the kit with fresh gear lube.
- Install the new O-rings onto their respective plugs, ensuring they are seated correctly in the groove.
- Reinstall the drain screw and fill the outdrive with the manufacturer-specified gear lubricant through the bottom hole until it flows from the upper vent hole.
- Reinstall the upper vent screw/dipstick. Tighten both plugs to the torque specified in your service manual.
- Check for leaks after running the engine.
Troubleshooting & FAQ
What specific plugs do these O-rings fit?
This kit contains the three essential O-rings for a lower unit service: one for the dipstick (replaces 3852045), one for the gear oil vent plug, and one for the gear oil drain plug (both replace 3855081).
Will this fit my specific Volvo Penta SX-A drive?
Yes, this kit is designed for the SX-A series, along with SX-M, DPS-A, and DPS-B drives across their various gear ratios. It's always best to confirm your OEM part number, but these models are the primary application.
How do I know if my old O-rings have failed?
Signs of failing O-rings include visible gear oil weeping or dripping from the drain/vent plugs, or a milky/watery appearance in the gear lube when you drain it, which indicates water intrusion past a failed seal.
Is this kit also for OMC Cobra or Johnson/Evinrude engines?
Yes, the part numbers cross-reference to applications in OMC Cobra upper gear cases and various Johnson/Evinrude loopcharged outboard gearcases. Please consult your service manual to confirm part number 303067, 329381, 332584 or 3852045 is correct for your model.
What is the recommended replacement interval?
It is best practice to replace these O-rings every time you change your outdrive's gear lube, which is typically recommended annually or every 100 hours of operation, whichever comes first.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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