Lower Unit Gearcase Seal Kit for Volvo Penta SX Sterndrives Through 2006 – Replaces 3855275
Lower Unit Gearcase Seal Kit for Volvo Penta SX Sterndrives Through 2006 – Replaces 3855275 is backordered and will ship as soon as it is back in stock.
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Lower Unit Gearcase Seal Kit for Volvo Penta SX Sterndrives Through...
Lower Unit Gearcase Seal Kit for Volvo Penta SX Sterndrives Through 2006 – Replaces 3855275 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Lower Unit Gearcase Seal Kit is intended for Volvo Penta SX sterndrives through 2006. The company fitment information specifically lists SX-C, SX-C1, SX-C2, SX-CT, SX-CT1, SX-CT2, SX-M, SX-M1, SX-MTD, SX-MTD3, SX-RT1, and SX-RT2 models.
The kit is listed as a replacement for Volvo Penta OEM numbers 3855275 and 0778351. Sierra 18-2598 is the documented aftermarket reference for this seal kit. Always compare the original component and sterndrive model before ordering.
- Gear housing and lower unit seal kit for Volvo Penta SX applications.
- Designed to help restore sealing at serviced gearcase locations.
- Professional installation is recommended because lower-unit disassembly and seal replacement require specialized procedures.
Part Number Matrix
The following numbers are supplier-listed OEM, aftermarket, or reference numbers associated with this gear housing seal kit. They are provided for identification and cross-reference purposes; verify the application before purchase.
| Brand or Reference | Part Number | Reference Type |
|---|---|---|
| Volvo Penta | 3855275 | OEM reference |
| Volvo Penta | 0778351 | OEM reference |
| Sierra | 18-2598 | Aftermarket reference |
| SEI Marine | 95-115-11K | Supplier-listed reference |
| GLM | 87750 | Supplier-listed reference |
| Evinrude / Johnson / OMC / BRP | 778351 | Supplier-listed reference |
Engine & Model Compatibility
Fitment is determined by the sterndrive model and gear housing configuration rather than by engine displacement alone. The company application is for Volvo Penta SX sterndrives through 2006, including the model variants below.
| Brand | Drive Family | Application Range | OEM Reference | Notes |
|---|---|---|---|---|
| Volvo Penta | SX-C, SX-C1, SX-C2 | Through 2006 | 3855275 / 0778351 | Lower unit gearcase seal kit |
| Volvo Penta | SX-CT, SX-CT1, SX-CT2 | Through 2006 | 3855275 / 0778351 | Lower unit gearcase seal kit |
| Volvo Penta | SX-M, SX-M1, SX-MTD, SX-MTD3 | Through 2006 | 3855275 / 0778351 | Lower unit gearcase seal kit |
| Volvo Penta | SX-RT1, SX-RT2 | Through 2006 | 3855275 / 0778351 | Lower unit gearcase seal kit |
Technical Specs
- Product Type
- Lower unit gearcase seal kit
- Application
- Volvo Penta SX sterndrives through 2006
- Installation
- Professional installation recommended
- OEM References
- 3855275 and 0778351
- Aftermarket Reference
- Sierra 18-2598
What's in the Box
This listing is for one lower unit gearcase seal kit. The company source identifies the product as a gear housing seal kit but does not provide a verified itemized component list or quantities. Do not assume that individual seals, O-rings, water-tube seals, or gaskets shown in another application are included unless they are confirmed against the supplied kit.
Installation Notes
- Confirm the sterndrive model and compare the original seal kit or OEM reference before beginning work.
- Disconnect the battery and follow the sterndrive manufacturer's safety procedures.
- Drain the gearcase lubricant into a suitable container and inspect it for water contamination or metal debris.
- Remove the propeller and lower unit according to the manufacturer's service procedure.
- Disassemble only as required to access the seals and sealing surfaces.
- Remove old seals carefully to avoid damaging shafts, bores, mating surfaces, or the gear housing.
- Clean and inspect all sealing surfaces before installing replacement components.
- Install the new seals using the correct tools, orientation, lubricant, and sealant specified by the service manual.
- Reassemble the lower unit and torque all fasteners to the manufacturer's specifications.
- Refit the lower unit, refill it with the manufacturer's specified marine gear lubricant, and install the plugs with serviceable seals.
- Inspect for leaks before operating the vessel and recheck lubricant condition after an initial test run.
Troubleshooting & FAQ
How do I know if my gearcase seals may be failing?
Possible indicators include milky or water-contaminated gear lubricant, visible lubricant around the gearcase or propeller-shaft area, or a recurring loss of lubricant. A pressure or vacuum test performed with the correct service equipment can help locate a leak.
Which drives does this kit fit?
The company application is for Volvo Penta SX sterndrives through 2006, including SX-C, SX-C1, SX-C2, SX-CT, SX-CT1, SX-CT2, SX-M, SX-M1, SX-MTD, SX-MTD3, SX-RT1, and SX-RT2. Confirm the exact drive variant and original part number before ordering.
Is this an OEM part?
No. This is an aftermarket replacement seal kit. The listed OEM numbers are provided as application references and do not indicate that the kit is manufactured by Volvo Penta.
Does the kit include every seal and O-ring shown in other listings?
Not necessarily. The company source identifies this product as a gear housing seal kit but does not publish a verified itemized contents list. Confirm the package contents before installation if a specific seal or gasket is required.
Should I install the kit myself?
Professional installation is recommended. Lower-unit seal replacement may require specialized pullers, drivers, pressure-testing equipment, service specifications, and careful alignment of internal components.
What should I check before ordering?
Check the sterndrive model designation, model year or production range, original seal-kit number, gear housing configuration, and the physical dimensions or appearance of the original components. A model that appears similar is not sufficient confirmation of fitment.
Safety & Important Information
- Use the manufacturer's service manual for disassembly, seal orientation, torque values, lubricant specifications, and pressure-testing procedures.
- Do not operate the vessel if the gearcase shows lubricant leakage or water contamination.
- Verify the complete sterndrive identification and original part number before purchase.
- This is an aftermarket replacement part, not an Original Equipment Manufacturer component.
- Professional installation is strongly recommended.
About Sea Sierra
- Marine Replacement Parts — We supply replacement components for service and repair applications.
- Application-Focused Information — Product references and fitment details are provided to help customers compare their original part and drive model.
- Support for Proper Selection — When model or part-number details differ, verify the application before ordering or consult a qualified marine technician.
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