Transom Gasket Seal – Fits MerCruiser Alpha 1 Gen 2 & All Bravo Engines (Replaces 43713)

$16.00

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Transom Gasket Seal – Fits MerCruiser Alpha 1 Gen 2 & All Bravo Engines (Replaces 43713) is backordered and will ship as soon as it is back in stock.

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Product Details

This aftermarket Transom Gasket Seal – Fits MerCruiser Alpha 1 Gen 2 & All Bravo Engines (Replaces 43713) creates a watertight seal between the transom and gimbal housing. It is designed for Mercury MerCruiser Alpha One Gen II (1991–2002) and all Bravo I, II, & III sterndrive models from 1988 to 2002.

It serves as a direct replacement for MerCruiser 43713, Sierra 18-2724, GLM 86711, Mallory 9-72420, and UanofCn 43713.

Installs between the transom assembly and gimbal housing.
Engineered from marine-grade CR rubber for durability in saltwater and freshwater environments.
Provides a reliable, watertight seal to prevent leaks into the bilge.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
MerCruiser	43713
Sierra	18-2724
GLM	86711
Mallory	9-72420
UanofCn	43713

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser owners, verify your model and engine serial number range to ensure a precise fit. This gasket is compatible with Alpha One Gen II and all Bravo series outdrives within the specified serial numbers.

Model	Years	OEM Part No.	Notes
Alpha One Gen II	1991–2002	43713	Serial Range: 0D469859 & Up
Blackhawk	1994–1995	43713	Serial Range: 0F186717 & Up
Bravo I	1988–2002	43713	Serial Range: 0B664190 & Up
Bravo II	1988–2002	43713	Serial Range: 0B664190 & Up
Bravo III	1988–2002	43713	Serial Range: 0B664190 & Up

Technical Specs

Product Type: Transom Gasket Seal
Installation: Mounts between transom and gimbal housing
Material: Marine Grade CR Rubber
Color: Black
Weight: 0.1 lbs (0.045 kg)

What’s in the Box

1 x Transom Gasket Seal (43713)

Installation Notes

Safely disconnect the vessel's battery and any relevant power sources.
Remove the sterndrive unit according to the manufacturer's service manual to access the transom assembly.
Carefully detach the gimbal housing from the transom to expose the old gasket seal.
Remove the old, worn gasket and thoroughly clean both mounting surfaces of any residue, corrosion, or old sealant.
Align the new transom gasket seal and position it correctly between the gimbal housing and transom.
Re-secure the gimbal housing, ensuring all bolts are tightened to the specified torque. Reinstall the sterndrive and test for leaks in the water.

Troubleshooting & FAQ

How can I confirm this gasket is the right one for my MerCruiser engine?

Check the Engine & Model Compatibility table on this page. Verify that your engine model, year, and serial number fall within the specified ranges. Comparing the OEM part number (43713) to your service manual is the most reliable method.

What are the common signs that my transom gasket is failing?

The most common symptom of a bad transom seal is water leaking into the boat's bilge area from the transom assembly. You may notice this after the boat has been in the water or during operation. A visual inspection may also reveal cracking, brittleness, or deformation of the rubber seal.

How often should this transom seal be replaced?

There is no fixed replacement interval, but the seal should be inspected annually for signs of wear, drying, cracking, or damage. It is often recommended to replace it preventatively whenever the sterndrive is removed for other major service.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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