Transom leak

Boat - 2004 Sea Ray 300DA

OK.... last year was my first year with the boat. I had some water sitting between the stringers pretty much all summer however only heard the pumps come on a couple of times. I was led to believe that some water in the engine bilge is kinda normal. I launched the boat last Thursday. From the launch location to the marina is about a 8 minute low speed drive. By the time I tied up in my slip and shut the engines down I heard the bilge pump come on. I quickly popped the hatch and saw water in the center between and stringers and also outside of the starboard stringer where I had NOT seen it last year. Of course when I launched it was all dry. I watched the water for a bit and determined that it was about a 8 minute cycle between the pumping cycles. I ran back to the marina and grabbed "my" technician. He came aboard and within a couple of minutes (and some very contorted positions) he was able to locate leaks coming from behind or around both transom plates. We then pulled the boat out pretty quickly and put it back inside. Pulled both bilge bolts and drained it. I sat with the marina service manager for a while and he explained to me what I was up against. obviously the engines need to be pulled and transom inspected. He was pretty pessimistic about where I stood and painted with pretty broad strokes about possibilities. Later in the afternoon he and I went back to the boat and he brought a small metal hammer and "pinged" the entire transom. He said (much to his surprise) that the entire thing sounded really good yet and his optimism raised a bit. The plan is to start pulling the engines and see whats up.

Of course this has all had me in a tail spin and thought I ought to head here and ask some questions of guy who have been around the "boating block" a few times.

- anyone been here before on a similar boat to mine?
- anyone know the transom construction on a 2004 300DA? is there wood? manager used the phrase of "damage to the substrate"
- is this typical for a 17 year old boat?
- where do you think I stand?

Had a similar issue on an older SR. Water was coming in around the transom assembly. Ultimately found rotten transom collapsed and loosened the transom assembly bolts/studs and caused the leak. Engine out, drive off, transom assembly off, and transom stripped of hardware inside and out. New transom installed by me from the inside. Reassembled and bilge was dry as a bone for the rest of the years I owned it. Friend bought it and also never had water in again. I realize this is worst case but something to be mindful of.

Start with this question -- did you have it surveyed when you bot it? Did said survey reveal any transom issues?

OOooOOoooooo

Good luck with the repair. Little bit strange that they both went bad all of a sudden.

I'm wondering if one of the bellows didn't split or something similar vs transoms.

When you stored the boat over winter was the outdrives up or down?

Shift cable bellows? Steering Arm? Two common places for leaks in a Bravo III - shift cable bellows on any outdrive - that is usually the first of the bellows that starts leaking and they can leak quite a bit of water. Could also be the U-Joint bellows. Just seems strange that both transom assemblies started leaking at the same time.

Worst case - what happens on the transom assembly is it is never sealed correctly from installation and if the transom cutout is not sealed leaving exposed wood coring (transom has wood in it). Over time water seeps in around the transom assembly and wicks into the wood core rotting it - by the time you see leaking around the transom assembly, the transom is rotted around the cutouts to the point there is flexing in the transom around the assemblies - then the leaking starts.

Best case you have a leaking shift cable bellows OR the transom assembly seal is just leaking (I think it is only a foam gasket) and there is no rot in the transom. In this case you might could just re-tighten the bolts that hold the transom assembly in (it it just sandwiches the transom).

Unless the transom assemblies look bad - rusted etc - I would do some more investigation before I start pulling engines etc. Eliminate the other (cheaper) possibilities first.

Little Ducky said:

OOooOOoooooo

Good luck with the repair. Little bit strange that they both went bad all of a sudden.

I'm wondering if one of the bellows didn't split or something similar vs transoms.

When you stored the boat over winter was the outdrives up or down?

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They were down....

BillK2632 said:

Shift cable bellows?

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were told they were replaced and have a invoice from 12/2019

Golfman25 said:

Start with this question -- did you have it surveyed when you bot it? Did said survey reveal any transom issues?

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"yes" and "no"

I was thinking bellows as well.

I had a similar issue with my 2001 Monterey, twin 5.7 with Bravo III outdrives. The bilge pump would cycle about every 10 mins. I would shop vac it dry once back at the marina, and then into the boatel it went. Next trip, same thing.

Service shop put a camera in the engine compartment and the drive. I forget what it was but there was a small raw water leak in the drive. About a $500 repair if I recall. I never had it fixed since the boat stayed in the boatel.

Did your mechanic put a camera on/in it?

mrsrobinson said:

I was thinking bellows as well.

I had a similar issue with my 2001 Monterey, twin 5.7 with Bravo III outdrives. The bilge pump would cycle about every 10 mins. I would shop vac it dry once back at the marina, and then into the boatel it went. Next trip, same thing.

Service shop put a camera in the engine compartment and the drive. I forget what it was but there was a small raw water leak in the drive. About a $500 repair if I recall. I never had it fixed since the boat stayed in the boatel.

Did your mechanic put a camera on/in it?

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Yes, there is a video of them both leaking. you can view it running. He was very specific in the fact it's coming from between the transom and plate. Ruled out boot and bellows. I am not certain if it can be ruled out that easily but thats what he said.

Sounds like you have a good mechanic

I would reach out to Sea Ray (865-971-6250) and ask specifically about what if any coring is used in your hull. I would be surprised if there was wood coring in the structural transom, but often, there is a a plywood backer glassed in to the backside of the transom for equipment and swim platform mounting purposes. If that backer is also present behind the drive mounting flange and is rotting, indeed could cause drives to loosen and leak.

amajamar said:

I would reach out to Sea Ray (865-971-6250) and ask specifically about what if any coring is used in your hull. I would be surprised if there was wood coring in the structural transom, but often, there is a a plywood backer glassed in to the backside of the transom for equipment and swim platform mounting purposes. If that backer is also present behind the drive mounting flange and is rotting, indeed could cause drives to loosen and leak.

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Thank you sir... calling shortly

Called them up and he said it is not a cored hull. It may have some wood in for the exact use you specified however.

JackLabs said:

Thank you sir... calling shortly

Called them up and he said it is not a cored hull. It may have some wood in for the exact use you specified however.

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You may want to ask specifically if there is any plywood behind the drive backing plate. They should be able to say definitively. If they say no, then that would be much better news.

You'll have your answer when you remove a TA, the rot starts at the key-hole.

JackLabs said:

"yes" and "no"

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Ok, that sounds good. That plus you're hammer experiment indicate that there isn't a major transom repair likely -- catching it early. I would get a moisture meter and check it, or have a surveyor do the same. You'll probably need to remove some of the antifouling paint to do so. The other options are judicious drilling into the core looking for moisture or removing a bolt/fitting to see if water seeps out. I would want to rule out anything in the transom before I proceeded. As others have said, the bellows and other areas are possibilities. Good luck.

JackLabs said:

Boat - 2004 Sea Ray 300DA

- is this typical for a 17 year old boat?

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We looked at a 2007 260DA. Water was leaking in through the transom assembly and the whole transom assembly had to be replaced. The surveyor we used said it was typical for a boat that age.

Seeing that there is at least a half dozen points of water entry in that area, I confirm the transom seal by putting a bead of caulking around the TA to transom joint.

amajamar said:

I would reach out to Sea Ray (865-971-6250) and ask specifically about what if any coring is used in your hull. I would be surprised if there was wood coring in the structural transom, but often, there is a a plywood backer glassed in to the backside of the transom for equipment and swim platform mounting purposes. If that backer is also present behind the drive mounting flange and is rotting, indeed could cause drives to loosen and leak.

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There absolutely is wood in the transom.

Drill a hole from the inside and check for rot. May have to drill several spots. The holes should be filled with epoxy if found to be dry.

One way I definitively found my leak was to put the drain plug in and fill the bilge with water. Obviously don't fill it above the starter or anything else electrical. Mine was leaking from around the transom shield.

Confused said:

One way I definitively found my leak was to put the drain plug in and fill the bilge with water. Obviously don't fill it above the starter or anything else electrical. Mine was leaking from around the transom shield.

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That's how my shop found my leak was coming from connection of the exhaust Y pipe and inner transom plate, worked great!