26-830749A01 Seal Kit Lower Gearcase for Mercury Mariner Force Verado | JLM Marine

Seal Kit Lower Gearcase for Mercury Mariner Force Verado 135-300HP | 26-830749A01

This lower gearcase seal kit is engineered for Mercury, Mariner, and Force Verado outboards from 135 HP to 300 HP, covering 4-cylinder and 6-cylinder FourStroke models from 2005 to current. Designed to fit the 4.80-inch Torpedo gearcase, it ensures reliable sealing and protection for your lower unit in demanding marine environments.

This aftermarket seal kit directly replaces OEM part number 26-830749A01 and cross-references with Sierra 18-2725, GLM 87515, and Mallory 95-221-11K. It provides a complete sealing solution for routine maintenance or gearcase rebuild projects.

• Fits 200/225/250/275 HP FourStroke Verado outboards beginning with Model Year 2005
• Complete seal kit includes all components shown in product images
• Compatible with 4.80-inch Torpedo gearcase configurations

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 Mercury owners, here's a guide to help you identify your engine's serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

This seal kit includes:

• 1x Gearcase Seal Kit
• The package contains all the parts shown in the product images

Installation Guide

1. Disconnect the battery and raise the outboard to full tilt position. Remove the lower unit from the motor following your service manual procedures.
2. Drain all gear oil completely and clean the gearcase exterior. Remove the propeller, propeller shaft, and carrier assembly.
3. Carefully remove all old seals, gaskets, and O-rings from the gearcase housing and shafts. Clean all mating surfaces thoroughly, removing residue and corrosion.
4. Inspect all seal surfaces for scoring, pitting, or wear that may prevent proper sealing. Replace any damaged components as necessary.
5. Apply marine-grade grease to new seal lips before installation. Install new seals with the lip facing the correct direction per your service manual.
6. Install O-rings and gaskets in their proper locations, ensuring they seat evenly without twisting or pinching. Do not reuse old seals or gaskets.
7. Reassemble the propeller shaft and carrier assembly, ensuring proper bearing alignment. Torque all fasteners to manufacturer specifications.
8. Reinstall the lower unit onto the motor, aligning the shift shaft carefully. Secure all mounting bolts to the specified torque.
9. Refill the gearcase with the manufacturer-recommended gear oil type and quantity. Check for proper oil level through the vent and fill plugs.
10. Run the engine in a test tank or on the water, checking for leaks around all seal areas. Monitor gear oil level after initial run and top off if needed.

Troubleshooting & FAQ

Q: How do I confirm this seal kit fits my Mercury Verado outboard?
A: Verify your engine's HP rating (135-300 HP), model year (2005 or newer), and confirm it has the 4.80-inch Torpedo gearcase. Cross-reference your original OEM part number 26-830749A01 with the product listing.

Q: What are the signs that my lower unit seals need replacement?
A: Common symptoms include milky or discolored gear oil (water contamination), visible oil leaks around the lower unit, excessive gear noise, or oil level dropping between services. Replace seals immediately if water intrusion is detected.

Q: How often should I replace the lower gearcase seals?
A: Replace seals during major lower unit service (typically every 3-5 years or 300-500 hours), whenever the lower unit is disassembled for repair, or immediately if leaks or water contamination are observed during routine oil changes.

Q: Can I install this seal kit myself or do I need a mechanic?
A: Installation requires disassembly of the lower unit, proper seal installation techniques, and torque specifications. If you have mechanical experience and the proper service manual, DIY installation is possible; otherwise, professional installation is strongly recommended.

Q: Does this kit include all seals needed for a complete lower unit rebuild?
A: This kit contains all seals and gaskets shown in the product images for the lower gearcase. Verify the components against your service manual to ensure complete coverage for your specific rebuild needs.

Q: What is the difference between this aftermarket seal kit and the OEM version?
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.