Lower Unit Gearcase Seal Kit – Fits Johnson/Evinrude 40-50 HP (Replaces 433550)

Lower Unit Gearcase Seal Kit – Fits Johnson/Evinrude 40-50 HP (Replaces 433550)

This lower unit gearcase seal kit is designed for Johnson/Evinrude 2-cylinder 40 HP, 48 HP, and 50 HP 2-stroke outboard motors from 1989-2005.

It serves as a direct replacement for Johnson/Evinrude part number 433550, Sierra 18-2694, GLM 87614, and Mallory 9-74104.

• Installation: Direct replacement
• Compatibility: Complete kit for Johnson/Evinrude 2-cylinder 40-50 HP gearcase service
• Fuel Type: Gasoline

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.

Technical Specifications

Package Contents

• 1 x Complete Lower Unit Seal Kit (Replaces 433550)

Installation Guide

1. Ensure the engine is turned off and the battery is disconnected. Drain the gearcase oil completely into a suitable container.
2. Remove the propeller assembly, followed by the lower unit (gearcase) from the outboard motor.
3. With the lower unit on a workbench, carefully remove the old seals, noting their positions and orientations.
4. Thoroughly clean all sealing surfaces, removing any old sealant, corrosion, or debris.
5. Lightly lubricate the new seals with marine grease before installation.
6. Carefully press the new seals into place using an appropriate seal driver, ensuring they are seated evenly and at the correct depth.
7. Reassemble the lower unit components in the reverse order of disassembly.
8. Reinstall the lower unit onto the outboard motor and attach the propeller.
9. Refill the gearcase with the manufacturer-specified gear lube to the proper level.
10. Before operating, check for any signs of leaks around the seals.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my Johnson/Evinrude engine?
A: This kit is designed for 2-cylinder 40 HP, 48 HP, and 50 HP models from 1989-2005. Always verify your specific model and year against the compatibility chart and check that your original part number is 433550.

Q: Some stores say this fits a 25 HP model. Is that correct?
A: While our primary confirmed fitment is for 40-50 HP models, some sources suggest compatibility with 25 HP engines from the same era. We recommend verifying the OEM part number (433550) for your 25 HP engine before purchasing to ensure a correct fit.

Q: What are the signs my gearcase seals are failing?
A: Common signs include milky or water-contaminated gear lube, visible oil leaks around the propeller shaft or driveshaft, or a metallic sheen in the oil, indicating water intrusion and potential gear wear.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.