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Why is Water Leaking Into My Boat?

Does your automatic bilge pump constantly cut on?
You might have a leaking transom assembly.

The "transom assembly" is actually the Gimbal Housing Assembly.
The Gimbal Housing assembly has rubber components that can rot and/or rip and leak.
The two rubber components most likely to cause a water leak are the Ujoint Bellows and the Shift Cable Bellows.

Replacing the Shift Cable Bellow requires removal of the drive and replacement of the shift cable.

Contrary to common belief, the Exhaust Bellows will not allow water to leak into the boat.

The rubber bellows should be replaced about every five years or sooner if you suspect a leak.
Read more about replacing your Ujoint Bellows at:
Alpha One Bellows
Alpha Gen II Bellows
Bravo Bellows

If you have water leaking into the boat, be glad you noticed it!
The drive should be immediatly removed as to stop any more damage and repair the leak.
Water is were it shouldn't be and this will eventually ruin the gimbal and sterndrive unit.

Water can leak in other areas as well.
It can leak in at the top of the gimbal ring where the steering shaft passes into the boat. There is a seal which holds the water out but the shaft is hardened steel which can rust, pit and ruin the seal. This requires removal of the gimbal ring. Buy a Service Manual before attempting this repair.

Water can also leak into the boat from a corroded exhaust pipe.
The exhaust pipe leads down from the engines exhaust elbow to the inner transom.
It's an aluminum pipe which can corrode through and leak.
To check the pipe for leaks, haul the boat out of the water and run the engine on a garden hose.
Take a flashlight and look under the engine towards the transom and look for water dripping in the bilge.
If you see any water, chances are good you have a leaking exhaust pipe.
The engine must be removed to replace the pipe.

Another trick to locate a "mystery leak" is to fill the bilge with water with the bow up high.
Obviously this is done on the trailer out of the water.
Chaulk your trailer wheels and raise the bow of the boat up as high as possible. Install your boats drain plug and start filling the bilge with fresh water. Carefully monitor the level of that water as so it doesn't get too high. Avoid letting it get up to the starter motor. Stand behid the boat and look for water dripping out.

Water can also leak into the bilge from a leak on the engine. This will only be noticed when the engine is running. While the engine is running, use a flashlight and inspect the entire engine and bilge areas. A loose or damaged hose or a popped out freeze plug can leak water.

Change your Alpha Gear Lube
Change your Bravo Gear Lube
Why does my drive lube have white streaks?
Why does my drive lube have gray mush?
Replace Your Alpha One Water Pump
Replace your Alpha Gen II Water Pump
Rebuild your Bravo Raw Water Pump

Troubleshoot & Replace your Alpha Shift Cable
Troubleshoot & Replace your Bravo Shift Cable

Replace your Alpha One Bellows & Gimbal Bearing
Replace your Alpha Gen II Bellows & Gimbal bearing
Replace your Bravo Bellows & Gimbal Bearing
Why does my drive "Growl" when I turn?
Water is leaking into my boat from the transom

Replacing your Trim Sender Switches
My Trim doesn't work but my Trailer Switch does
My Trim Gauge is Pegged

Rebuild your Alpha One Upper Driveshaft Housing Assembly
Rebuild your Alpha One Lower Gear Housing Assembly

Check your Engine Alignment
Check for Excessive Steering Play
Troubleshoot an Overheating Problem
Should I remove my thermostat?
Why do I overheat when going fast?
Troubleshoot a No-Crank Condition
Troubleshoot a No-Start Condition
My Engine Backfires and/or Surges and has Lack of Power
What is an Anti-Syphon Valve?
My Engine blows Steam from the Exhaust
Why do I hear a "clakity" sound while at idle?
Exhaust Manifolds...IMPORTANT Information
How do I Winterize my engine?

What is Galvanic Corrosion?
I have a Bravo III Galvanic Corrosion Problem
What is a Mercathode?
All about Zinc Anodes
How do I check my carburetor?
What carburetor do I have? A Rochester or a Mercarb?
I have water in my fuel
My fuel smells like varnish
My fuel is old
My engine has been sitting for several months without being run.

I have a Mercruiser 470, 485, 488, 190, 3.7L Engine
I have coolant dripping from the front of my engine
Can I install a regular Alternator instead of the Stator-Rotor?

Converting an OMC to a Mercruiser

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