Driveshaft Housing Upper Unit Seal Kit – Fits Mercruiser Alpha One Gen II (Replaces 26-88397A1)

Driveshaft Housing Upper Unit Seal Kit – Fits Mercruiser Alpha One Gen II (Replaces 26-88397A1)

This seal kit is designed for Mercruiser Alpha One Generation II stern drives from 1991 and newer. It contains all the necessary seals for servicing the upper driveshaft housing to prevent water intrusion and oil leaks.

This kit is a direct replacement for Mercruiser part number 26-88397A1 and other aftermarket equivalents.

• Installation Method: Direct replacement for the original seals.
• Compatibility: Specifically engineered for Alpha One Gen II (1991–Present) upper units.
• Complete Kit: Includes all required seals for a standard upper driveshaft housing rebuild.

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.

Technical Specifications

Package Contents

• 1 x Upper Driveshaft Housing Seal Kit (replaces 26-88397A1)

Installation Guide

Professional installation is recommended. The following are general steps for replacement:

1. Safety First: Disconnect the boat's battery before starting work.
2. Drain Fluids: Drain the gear lube from the sterndrive completely.
3. Disassemble Drive: Separate the upper and lower sterndrive units according to your service manual.
4. Remove Old Seals: Carefully remove the old seals from the upper driveshaft housing, taking care not to scratch the metal surfaces.
5. Clean Surfaces: Thoroughly clean the seal seating areas to ensure a perfect fit for the new seals. Remove any old sealant or corrosion.
6. Install New Seals: Gently press the new seals into place using an appropriate seal driver or socket. Ensure they are seated evenly and at the correct depth.
7. Reassemble: Reassemble the upper and lower units, replacing any other necessary gaskets or O-rings.
8. Refill and Check: Refill the sterndrive with fresh, high-quality marine gear lube. Once filled, check for any signs of leaks around the newly installed seals.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my Mercruiser drive?

A: This kit is specifically for Mercruiser Alpha One Generation II drives manufactured from 1991 to the present. You should verify your drive model and year before ordering. The compatible OEM part number is 26-88397A1; cross-referencing this number is the best way to ensure compatibility.

Q: What are signs that my upper driveshaft seals are failing?

A: The most common sign of a failed seal is water intrusion into your gear lube, which gives the oil a milky or cloudy appearance. You might also notice gear oil leaking externally from the seams of the upper drive unit.

Q: How often should I replace these seals?

A: For preventative maintenance, it is recommended to inspect your seals annually and consider replacement every 1-2 seasons, especially if operating in saltwater. They should be replaced immediately if you notice any signs of leakage or water contamination.

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.