Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40–50 HP 2-Cylinder Outboards – Replaces 433550
Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40–50 HP 2-Cylinder Outboards – Replaces 433550 is backordered and will ship as soon as it is back in stock.
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Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40–50 HP 2-Cylind...
Lower Unit Gearcase Seal Kit for Johnson/Evinrude 40–50 HP 2-Cylinder Outboards – Replaces 433550 is backordered and will ship as soon as it is back in stock.
Product Details
This Lower Unit Gearcase Seal Kit is intended for selected Johnson/Evinrude 2-cylinder loopcharged 40 HP, 48 HP, and 50 HP 2-stroke outboards with the small gearcase housing. Catalog application data covers models manufactured from 1989 through 2005.
The kit is an aftermarket replacement for the Johnson/Evinrude/OMC gearcase seal kit reference 433550. Catalog cross-references identify Sierra 18-2694 and GLM 87614 with this application. Always compare the engine model, year, gearcase housing, and original part number before ordering.
- Replacement lower unit or gearcase seal kit for selected Johnson/Evinrude outboards.
- Designed for mechanical-shift gearcases with thru-prop exhaust in the listed application range.
- Helps renew sealing points during lower unit service and reduce the risk of lubricant leakage or water intrusion.
- Aftermarket replacement; not an OEM-manufactured component.
Part Number Matrix
These are catalog references associated with this gearcase seal kit. A reference number alone does not replace verification of the complete engine and gearcase application.
| Brand or Catalog | Part Number | Reference Type |
|---|---|---|
| Johnson/Evinrude/OMC | 433550 | OEM application reference |
| Sierra | 18-2694 | Aftermarket cross-reference |
| GLM | 87614 | Aftermarket cross-reference |
Engine & Model Compatibility
Verify the complete model designation and gearcase configuration before purchase. The application below is limited to the documented 2-cylinder loopcharged small-housing gearcase range.
| Brand | Engine Application | Rated HP | Stroke | Years | Gearcase Condition | OEM Reference |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | 2-cylinder loopcharged outboards | 40 HP | 2-Stroke | 1989–2005 | Small housing; mechanical shift; verify exact model | 433550 |
| Johnson/Evinrude | 2-cylinder loopcharged outboards | 48 HP | 2-Stroke | 1989–2005 | Small housing; mechanical shift; verify exact model | 433550 |
| Johnson/Evinrude | 2-cylinder loopcharged outboards | 50 HP | 2-Stroke | 1989–2005 | Small housing; mechanical shift; verify exact model | 433550 |
Technical Specs
- Product Type
- Lower unit gearcase seal kit
- Application
- Selected Johnson/Evinrude 2-cylinder loopcharged 40–50 HP outboards
- Stroke
- 2-Stroke
- Gearcase Configuration
- Small housing; mechanical shift; thru-prop exhaust application
- Application Years
- 1989–2005, subject to exact model and gearcase verification
- Installation
- Replacement service part; professional installation recommended
- Fuel Type
- Gasoline outboard application
- Product Status
- Aftermarket replacement, not OEM
What’s in the Box
- 1 x Lower Unit Gearcase Seal Kit
- The kit is intended to replace the gearcase sealing components associated with the 433550 application.
- Exact seal styles and quantities can vary by kit production configuration. Compare the supplied components with the original gearcase parts before installation.
Installation Notes
- Confirm the engine model, year, horsepower, stroke, gearcase housing, shift type, and original reference number before beginning work.
- Place the outboard securely in a suitable service position and follow the manufacturer's service procedures.
- Drain the existing gearcase lubricant through the drain and vent openings, and inspect the lubricant for water contamination or metal particles.
- Remove the lower unit and disassemble only the gearcase components required for the seal service. Keep parts in removal order.
- Remove the old seals, gaskets, washers, and O-rings included in the service procedure. Clean sealing surfaces without damaging machined bores or shafts.
- Compare each replacement component with the removed part before installation. Install seals in the correct position and orientation using suitable marine lubricant or sealant where specified by the service manual.
- Reassemble the gearcase and torque fasteners according to the applicable Johnson/Evinrude service specifications.
- Refit the lower unit, fill the gearcase with the manufacturer's specified lubricant, and check for leaks before operating the outboard.
Troubleshooting & FAQ
How do I know if this seal kit fits my Johnson/Evinrude engine?
Confirm that your engine is a selected 2-cylinder loopcharged 40 HP, 48 HP, or 50 HP 2-stroke model from the 1989–2005 range and that it uses the documented small-housing mechanical-shift gearcase. Cross-reference the original gearcase seal kit number 433550 and verify the exact model in the manufacturer's service information.
Does this kit fit every Johnson/Evinrude 40–50 HP outboard?
No. Horsepower alone is not sufficient to confirm fitment. Gearcase housing, model year, shift configuration, serial range, and other model-specific conditions can affect compatibility.
What are common signs of failing lower unit seals?
Possible signs include milky or watery gear lubricant, lubricant leakage around the propeller shaft or drain screws, or repeated loss of gearcase lubricant. Inspect the complete gearcase before replacing seals.
Does the kit include the complete gearcase?
No. This listing is for a seal kit only. It does not include the lower unit housing, gears, shafts, bearings, propeller, or other gearcase assemblies unless specifically supplied with the kit.
Is this an OEM part?
No. This is an aftermarket replacement associated with the 433550 application and the listed aftermarket cross-references.
Should a professional install this kit?
Professional installation is recommended. Lower unit seal work requires correct disassembly, seal orientation, fastener torque, lubricant selection, and leak testing.
How often should lower unit seals be replaced?
There is no universal replacement interval. Inspect the gearcase during routine lubricant service and replace seals when leakage, water intrusion, damaged sealing surfaces, or other service findings indicate a need.
Safety & Important Information
- Verify the complete engine model, year, horsepower, stroke, gearcase housing, and original reference number before ordering.
- Do not rely on horsepower alone; similarly rated engines may use different gearcase components.
- Compare the supplied kit components with the original parts before installation.
- Use the applicable manufacturer's service manual for disassembly, seal installation, torque values, lubricant specifications, and leak testing.
- This is an aftermarket replacement, not an OEM component.
About Sea Sierra
- Marine Replacement Parts — Replacement components for servicing compatible marine systems.
- Application-Focused Listings — Product references and compatibility information are provided to support model and part-number verification.
- Service Support — Confirm your exact engine and gearcase details before ordering or contact support if application information is unclear.
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