Transom Gasket Gen 2 Bravo 43713

Function and technical context

The transom seal gasket acts as a watertight seal in the coupling zone between the engine block and the vessel's stern structure, preventing seawater from entering the hull interior through the transmission system passage point. In outboard drive systems such as MerCruiser's Bravo One, Bravo Two, Bravo Three and Alpha One Gen II assemblies, this gasket works in the hydromechanical transmission system, absorbing mounting stresses and sealing the transom shield perimeter against water pressure. Its deterioration causes leaks that can reach electrical and structural components in the bilge, generating accelerated corrosion in hard-to-reach areas and costly repairs to the stern structure. A worn transom gasket directly compromises the watertight integrity of the assembly and can cause the progressive entry of saltwater or freshwater into the hull interior without the operator noticing immediately.

When to replace this component?

The most common symptoms of transom gasket deterioration are the appearance of moisture or water stains in the lower stern area around the transom shield, presence of surface rust on the assembly fastening bolts, or detection of bilge seepage with no apparent cause. It is recommended to visually inspect this gasket at each seasonal maintenance interval and replace it whenever the propulsion unit is dismounted for any intervention on the transmission system or on the outboard drive bellows. Replacing the transom gasket preventively during a scheduled haul-out avoids structural corrosion damage and eliminates the risk of undetected leakage while underway.

Mercury / MerCruiser

Equivalent manufacturer references