Gear Lube Monitor Reservoir Kit – Fits MerCruiser Alpha One Gen 2, Bravo (Replaces 19742A1, 806193A48)

Gear Lube Monitor Reservoir Kit – Fits MerCruiser Alpha One Gen 2, Bravo

This gear lube monitor reservoir kit is designed for MerCruiser Alpha One Gen 2 (1988–1998) and Bravo (1991+) stern drives. It allows for easy monitoring of the gear lube level, which is a crucial preventative maintenance task to protect your drive from damage due to low oil.

This component is a direct replacement for Mercury part numbers: 19742A1, 19742A3, 19743A3, 19743A4, 806193A20, 806193A38, and 806193A48.

• Includes bottle, bracket, float switch, and sensor for a complete installation.
• Mounts on the transom or in the engine bay for flexible placement.
• Features a quick-connect fitting for the oil line to simplify setup.

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

• 1 x Gear Lube Bottle Assembly with Bracket (Replaces 19742A1)
• 1 x Strap
• 1 x Clip
• 2 x Screws
• 2 x Washers

Installation Guide

Always consult a certified marine mechanic if you are unsure about the installation procedure. Ensure the engine is off and the battery is disconnected before starting.

1. Safety First: Turn off the engine and disconnect the battery terminals.
2. Locate and Drain: Locate the old gear lube reservoir. Place a container underneath and carefully drain the old fluid by disconnecting the outlet hose.
3. Disconnect Sensor: Unplug the electrical connector for the fluid level sensor.
4. Remove Old Unit: Unscrew the mounting hardware securing the old reservoir and remove it from the boat.
5. Mount New Kit: Position the new reservoir assembly in the desired location (transom or engine bay) and secure it using the provided bracket, screws, and washers.
6. Connect Hose: Attach the gear lube hose to the hose barb on the bottom of the new reservoir, ensuring a tight fit to prevent leaks.
7. Connect Sensor: Plug the new sensor's electrical connector into the boat's wiring harness.
8. Fill with Lube: Fill the reservoir with the manufacturer-recommended gear lube to the indicated "Full" line. Do not overfill.
9. Inspect for Leaks: After filling, carefully inspect the hose connection and the bottle for any signs of leaks.
10. Final Checks: Reconnect the boat's battery. Start the engine and let it run for a few minutes, then re-check the fluid level and inspect for leaks again.

Troubleshooting & FAQ

How do I know if this gear lube monitor fits my MerCruiser engine?
This kit is specifically designed for MerCruiser Alpha One Gen 2 (1988-1998) and Bravo (1991+) stern drives. The best way to confirm fitment is to check your existing part number against the direct replacement numbers listed on this page, such as 19742A1 or 806193A48. Also, refer to our "Compatible Engine Models" table.

What is the purpose of the float switch and sensor?
The float switch and sensor are critical safety components. They continuously monitor the gear lube level inside the reservoir. If the level drops below a safe threshold, the sensor sends a signal to your boat's helm warning system, alerting you to a potential leak or low-lube condition before severe damage occurs to your stern drive gears.

What are the signs my current gear lube monitor is failing?
Common signs of a faulty monitor include visible cracks or hazing on the plastic bottle, persistent fluid leaks from the housing or hose connection, a low-lube alarm that won't turn off (even with a full bottle), or no alarm when the fluid is visibly low. Any of these symptoms warrant an inspection and probable replacement.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.