transom plate leak

Discussion in 'General Discussion' started by tallblue52, Jul 16, 2019.

  1. tallblue52

    tallblue52 New Member

    Mar 6, 2019
    1999 230 BR select
    350 bravo 3
    good afternoon, captains,
    my new to me 1999 230 bow rider with a newer 350 and bravo 3 has a very slight leak,
    how concerned should I be about this transom plate leak?
    thanks for any help
  2. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    No engines
    John, any leak in a boat can become a problem. For some, a dry bilge is a must. For others, a little water is acceptable. For me, the bigger question is why is it leaking. Whether its a nuisance or not is up to you and what you are willing to live with. And the bigger question is....will it get worse?

    It's unusual, but not unheard of, for the seal on the gimbal housing to develop a leak. (Gimbal housing is outside the boat, transom plate inside) Are you absolutely sure that is where the leak is from? There are a number of places where a leak could appear that looks like the gimbal housing seal but actually be from somewhere else. shift cable bellows is one that comes to mind. Is the transom solid? Yours would not be the first to have a transom develop a leak. Do you know if the gimbal housing has ever been removed for any reason.

    I would do all I could to track that sucker down again. Replacing the large O-ring is a big job as the drive has to come off and motor has to come out. I have a 1985, 23' Cobalt that lived in salt water for 29 years. A couple of years ago I had to replace the gimbal housing as it had deteriorated around the hinge pins. But it never leaked in all those years.

    So you need to make sure where the leak is coming from and then decide what to do about it.

    Good luck
  3. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    There are several places the transome assembly can leak - need to know where it is leaking.

    Common places for leaks:

    1. Shift cable bellows - address soon, it's only going to get worse. Can sink the boat.
    2. U-Joint bellows - address now, it's causing damage to the gimbal bearing and u-joints. Can sink the boat.
    3. Gear lube hose thru fitting. Monitor, replace fitting when convenient.
    4. Steering arm - monitor, depends on how bad it is. This is a common thing on BIII outdrives, steering swivel shaft bushings/seals wear and it starts leaking. The repair is somewhat involved, I would address that topic if you find out for sure that is what is leaking.

    Any leak should be addressed or at least understood, but if you trailer or dry store it might not be as pressing to fix. If you are in salt water then leaks are worse due to the salt water getting on things in the engine room. I'll give an example, when I was coming up on needing new bellows, my shift cable bellows starting leaking first - not much a drip that pretty much stopped with the drive trimmed down - it was October, I knew I was replacing it over the winter, so I let it go for a few weeks until the end of the season. But my boat is dry stored.
  4. tallblue52

    tallblue52 New Member

    Mar 6, 2019
    1999 230 BR select
    350 bravo 3
    thanks, guys, all good answers. the bellows are only 2 years old, and the boat has been in high and dry. this being my first bravo 3 I don't know if it reacts the same way as the alpha outdrives do. as the worst case may be pulling the engine out... I have never heard of a transom trim plate leaking... pulling the engine and replacing the trim plate is high $$$ trim plate alone is like 3K and pulling the 350 would be close to the same price as well. The one thing I noticed when checking out the boat was that the owner felt the raw water pump was not getting enough water, so, he put a through-hull in. and I can't help but wonder if he did not cap something off in the housing (trim plate to leak)
  5. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    The plug for the water intake could very well be leaking. The likely hood of the seal around the transom assembly leaking is possible, but unlikely. You need to spend some time in the bilge figure out where it is leaking. A beer, flashlight and an hour should give you some answers.
    JVM225 likes this.
  6. techmitch

    techmitch Well-Known Member GOLD Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    May be a bad case of Bravoitis.
  7. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass, cape coral fl
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    a 1999 could easily be the transom seal or y-pipe seal in addition to the more common areas mentioned above

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