Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40, 48 & 50 HP 2-Stroke Outboards — Replaces 433550, 18-2694, 87614 & 9-74104
Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40, 48 & 50 HP 2-Stroke Outboards — Replaces 433550, 18-2694, 87614 & 9-74104 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40, 48 & 50 H...
Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40, 48 & 50 HP 2-Stroke Outboards — Replaces 433550, 18-2694, 87614 & 9-74104 is backordered and will ship as soon as it is back in stock.
Product Details
This Lower Unit Gearcase Seal Kit is designed for servicing the gearcase on Johnson/Evinrude 2-stroke outboard motors rated at 40 HP, 48 HP, and 50 HP. Cataloged applications cover 2-cylinder models from 1989 through 2003. The kit helps renew the gearcase sealing points and protect the lower unit from lubricant leakage and water intrusion when installed correctly.
This aftermarket kit replaces Johnson/Evinrude/OMC part number 433550 and is cross-referenced with Sierra 18-2694, GLM 87614, and Mallory 9-74104. Always compare the part number and complete engine model information before ordering.
- Gearcase seal kit for selected Johnson/Evinrude 40, 48, and 50 HP 2-stroke outboards.
- Provides the seals required for the listed lower-unit gearcase service application.
- Suitable for repair or maintenance when the original seals show leakage, wear, or evidence of water intrusion.
- Aftermarket replacement component; not an OEM-branded part.
Part Number Matrix
These are manufacturer and aftermarket reference numbers associated with this gearcase seal kit. They are provided for identification and cross-reference purposes.
| Brand | Part Number | Reference Type |
|---|---|---|
| Johnson/Evinrude/OMC | 433550 | OEM reference |
| Sierra | 18-2694 | Aftermarket cross-reference |
| GLM | 87614 | Aftermarket cross-reference |
| Mallory | 9-74104 | Aftermarket cross-reference |
Engine & Model Compatibility
The documented application is for selected Johnson/Evinrude 2-stroke outboards with 40, 48, or 50 HP ratings and model years from 1989 through 2003. The application range is not a substitute for checking the exact model designation and gearcase configuration.
| Brand | Model Range | Rated HP | Stroke | Years | OEM Reference | Application Note |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | Selected 2-cylinder models | 40 HP | 2-Stroke | 1989–2003 | 433550 | Verify the complete engine model before ordering. |
| Johnson/Evinrude | Selected 2-cylinder models | 48 HP | 2-Stroke | 1989–2003 | 433550 | Verify the complete engine model before ordering. |
| Johnson/Evinrude | Selected 2-cylinder models | 50 HP | 2-Stroke | 1989–2003 | 433550 | Verify the complete engine model before ordering. |
Technical Specs
- Product Type
- Lower Unit Gearcase Seal Kit
- Application
- Selected Johnson/Evinrude 2-cylinder gearcases
- Rated Horsepower
- 40 HP, 48 HP, and 50 HP
- Stroke
- 2-Stroke
- Documented Model Years
- 1989–2003
- Installation
- Replacement during lower-unit gearcase service
- Fuel Type
- Gasoline
- Product Status
- Aftermarket replacement; not OEM-branded
What’s in the Box
- 1 × Lower Unit Gearcase Seal Kit
The kit is supplied as a complete seal-kit assembly for the stated application. Individual seal types and quantities may vary by the specific gearcase configuration; do not assume that unrelated water-pump or impeller components are included.
Installation Notes
- Confirm the engine brand, horsepower, stroke, model designation, year, and existing part-number reference before beginning work.
- Drain the gearcase lubricant completely and dispose of used lubricant according to local requirements.
- Disassemble the lower unit as required to access the seals, recording the orientation and order of removed components.
- Remove the old seals, O-rings, and gaskets carefully without scratching the sealing surfaces, housings, shafts, or bearing carrier.
- Clean the seal bores and shaft surfaces thoroughly and inspect them for corrosion, grooves, or other damage.
- Lubricate the replacement seals and O-rings with a suitable light coat of marine grease unless the service manual specifies another procedure.
- Install each seal in the correct orientation using an appropriate seal driver or installation tool. Do not strike the sealing lip directly.
- Reassemble the lower unit and torque fasteners according to the engine manufacturer's service specifications.
- Refill the gearcase with the recommended lubricant to the correct level and check for leaks before returning the engine to service.
Professional installation is recommended. Use the correct service manual for your exact model because gearcase designs, seal locations, and installation procedures can differ.
Troubleshooting & FAQ
How do I know if my gearcase seals are failing?
Common signs include milky or discolored gear lubricant, which may indicate water intrusion; visible lubricant leakage near the propeller shaft or driveshaft; or repeated loss of gearcase lubricant after operation. Inspect the gearcase and identify the source of the leak before replacing parts.
Will this kit fit a 25 HP Johnson/Evinrude motor?
The documented application for this listing is selected 40 HP, 48 HP, and 50 HP 2-stroke Johnson/Evinrude outboards from 1989 through 2003. A 25 HP application is not included in the documented fitment for this product. Verify your exact model and part-number reference before ordering.
Does this kit include an impeller or water-pump repair kit?
No. This listing is for a lower-unit gearcase seal kit. Impellers, water-pump repair kits, gearcase lubricant, and other components are not included unless specifically listed in the package contents.
Are special tools required for installation?
Depending on the engine and seal location, installation may require a seal puller, seal driver, appropriately sized sockets, and other lower-unit service tools. Follow the service manual for the exact engine and use tools that prevent damage to the housing and sealing surfaces.
What is the recommended replacement interval?
There is no universal fixed replacement interval for these seals. Inspect the gearcase during regular service and replace the seals when leakage, water intrusion, visible deterioration, or disassembly-related wear is found.
Is this an OEM part?
No. This is an aftermarket replacement kit intended for the listed application. The OEM and aftermarket reference numbers are provided only to help identify the correct replacement.
What should I verify before ordering?
Verify the engine brand, horsepower, 2-stroke configuration, model designation, model year, gearcase configuration, and the reference number from your original part or service documentation. Horsepower alone is not sufficient to confirm fitment.
Safety & Important Information
- Disconnect the battery and follow the manufacturer's safety procedures before servicing the outboard.
- Support and secure the engine and lower unit properly during removal and installation.
- Use the correct lubricant, seal orientation, torque values, and service procedures for the exact engine model.
- Do not operate the engine if the gearcase shows continuing lubricant leakage or evidence of water intrusion.
- Compare the original part and application details before purchase; this listing is not confirmed by horsepower alone.
- This is an aftermarket replacement, not an OEM-branded component.
About Sea Sierra
- Marine replacement parts selected for practical repair and maintenance applications.
- Clear cross-reference information to help identify compatible replacement components.
- Support for routine outboard service and lower-unit maintenance needs.
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