43713 Seal Gasket for Mercruiser Alpha One Gen 2 Bravo | JLM Marine

Seal Gasket for Mercruiser Alpha One Gen 2 Bravo – 43713

This transom gimbal housing mounting gasket is engineered for MerCruiser Alpha One Gen 2 and all Bravo stern drive marine engine models. It ensures a reliable seal between the gimbal housing and transom assembly, protecting against water intrusion and maintaining proper alignment during operation.

This aftermarket replacement directly replaces Mercury MerCruiser part number 43713 (also referenced as 3713) and Sierra 18-2724, offering a cost-effective solution without compromising fit or performance.

• Precision-cut gasket designed for Alpha One Gen 2 and Bravo stern drive systems
• Direct replacement for OEM part 43713
• Simple installation during gimbal housing service or transom assembly

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

Your purchase includes:

• 1 × Transom Gimbal Housing Seal Gasket (43713)

Installation Guide

1. Disconnect the battery and ensure the engine is completely off. Support the stern drive unit with a suitable jack or hoist.
2. Remove the drive unit by disconnecting shift cable, trim sender wires, and unbolting the drive from the gimbal housing. Carefully pull the drive away from the transom.
3. Inspect and clean the gimbal housing mounting surface and transom plate, removing all old gasket material and debris. Use a gasket scraper and solvent for thorough cleaning.
4. Remove the old transom gasket from the gimbal housing mounting flange. Check for any corrosion or damage on the mounting surfaces.
5. Position the new gasket (43713) on the gimbal housing mounting flange, aligning all bolt holes carefully. Ensure the gasket sits flat without wrinkles or folds.
6. Apply a thin bead of marine-grade sealant to both sides of the gasket if recommended by your service manual. This step may vary by application.
7. Reinstall the gimbal housing to the transom, aligning all mounting holes. Insert bolts finger-tight initially.
8. Torque the mounting bolts to manufacturer specifications in a crisscross pattern to ensure even compression. Refer to your MerCruiser service manual for exact torque values.
9. Reconnect the stern drive unit, ensuring proper alignment of the splines and u-joint. Reinstall all mounting hardware and torque to specification.
10. Reconnect shift cable, trim sender, and all electrical connections. Double-check all fasteners and connections.
11. Refill the drive unit with the correct stern drive lubricant to the proper level. Check for leaks around the new gasket.
12. Reconnect the battery, launch the boat, and perform a test run. Monitor for any leaks or unusual vibrations during operation.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my MerCruiser stern drive?
A: This gasket is designed specifically for Alpha One Gen 2 and all Bravo series stern drives. Verify your drive model by checking the identification tag on the transom assembly or gimbal housing. Cross-reference your existing part number (43713 or 3713 for Mercury, 18-2724 for Sierra) to ensure compatibility.

Q: When should I replace the transom gimbal housing gasket?
A: Replace this gasket whenever you remove the gimbal housing for service, repair, or when performing a sterndrive rebuild. Also replace it immediately if you notice water intrusion in the bilge near the transom, corrosion around the gimbal mounting area, or if the old gasket shows cracking, compression set, or deterioration.

Q: Can I reuse the old gasket if it looks okay?
A: No, always use a new gasket when reassembling the gimbal housing. Even if the old gasket appears intact, it has been compressed and may no longer provide a proper seal. Reusing gaskets can lead to water leaks, corrosion, and costly damage to internal components.

Q: Do I need to use sealant with this gasket?
A: Consult your MerCruiser service manual for specific recommendations, as requirements vary by model year and application. Some installations require a thin bead of marine-grade silicone sealant on both sides of the gasket, while others rely on the gasket alone. Follow the manufacturer's torque specifications for even compression.

Q: What are the signs of a failing transom gasket?
A: Common symptoms include water accumulation in the bilge (especially after running), visible corrosion or white residue around the gimbal housing bolts, water seeping from the transom assembly area, or a musty smell in the engine compartment. If you notice any of these signs, inspect and replace the gasket immediately to prevent structural damage.

Q: Is this an OEM part or 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.