Engine coming out again... 2nd time since being installed 4 years ago (or is it 5, who's counting).

J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
After having the motor out to reseal the transom and then having the transom fixed so that it was nice and flat the boat has developed a noise that is only present when it's in Neutral. 

I have taken it on 20+ mile trips with no issue, the saga is all blending together at this point. 

Yes I personally aligned the engine. Yes it has had two new gimbals and a transom kit in the last year and a half and even a complete new outdrive.

So it seems like it's just time to throw some more boat bucks at it and get it fixed. 

Anyone want to take a stab at what it might be?

Symptoms are:
- Knocking noise only when warm and in Neutral. 
- Cold and in neutral, no noise.
- Warm and in gear, no noise.
- To me I feel a vibration in gear and on plane, but some people say that's because of the hill marine props. 
- Noise does start to knock a little more when turning extreme right and left. 
- When boat is out of the water and running, the noise isolator scope (like a doctors stethoscope) shows the noise being the LOUDEST at the TOP of the out drive. Don't forget this out drive is new and the one previous to it made the same noise in the same spot! 

Take your best guess! Prize will be a pat on the back and a beer in the keys. Boat comes out in two weeks and will be on the hard for 4 weeks. 
Post edited by J3ff on
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Comments

  • Aqua_AuraAqua_Aura Member Posts: 2,620 ✭✭✭✭✭
    edited June 2021
    This started after installing the new outdrive? Maybe the outdrive is bad 🤷🏽‍♂️

    Nope nevermind mind I finished reading all the post 😃
    1997 Bayliner 3988
  • Aqua_AuraAqua_Aura Member Posts: 2,620 ✭✭✭✭✭
    What about the drive shaft, have you replaced that?
    1997 Bayliner 3988
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    I would assume the new drive came with a new drive shaft. No?
  • McGarnicleMcGarnicle Member Posts: 245 ✭✭✭
    Engine coupler? 
  • Aqua_AuraAqua_Aura Member Posts: 2,620 ✭✭✭✭✭
    I think they do but I'm not sure. Engine coupler? That seems to be about the only thing you haven't done. 
    1997 Bayliner 3988
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    Yes, that's what the mechanic is thinking, however there is no burned rubber smell.  My question is how does a coupler go bad with only 4 or 5 years and 150 hours on it. 
  • YYZRCYYZRC Member Posts: 5,111 ✭✭✭✭✭
    Flex plate. 
    2008 350 EC on Georgian Bay
  • PickleRickPickleRick Member Posts: 4,012 ✭✭✭✭✭
    edited June 2021
    The engine coupler is rubber and stiff rubber can deform.  I believe this is one of the reasons mercruiser recommends you clock the motor when checking alignment.


    The bravo is modeled after the old volvo Penta clutch style drive.  The 290 vovlo Penta didn't use an alignment bar, it had 3 notches behind the motor where it bolted to the transom housing that all had to be equal, you could measure the 3 points (2 sides and top) with the angled end of a paper clip. If they all slid in an equal amount she was aligned.


    The difference between the engine coupler of the Volvo Penta SBC and a mercruiser SBC?  The volvo Penta was all metal and sprung like a vehicle clutch.

    So, your transom was cockeyed for how long?  Unelss you clocked your engine during alignment you may have a well tweaked engine coupler or...out of round. 

    I don't think you'd have a burnt rubber smell if it's just deformed and out of round, you would have it off centered and causing vibration which also causes noise.

    Those couplers are not cheap at all iirc.  I remember one of the tdi conversion guys didn't like them with high torque applications.  I dont know how interchangeable they are but I have a low hour pre alpha 2pc rear seal chevy 305 parts motor that has one (early 80 model) that still has the coupler on it.  You can have it for the price of shipping if it will work for you.  The motor froze at just a few years old. I know the transom was good while bolted to the motor as I still have that too.  Stole one of the rear engine mount nuts off of it for my bravo 2 a few months ago.  
  • Dream_InnDream_Inn Member, Moderator Posts: 7,661 mod
    J3ff said:
    Yes, that's what the mechanic is thinking, however there is no burned rubber smell.  My question is how does a coupler go bad with only 4 or 5 years and 150 hours on it. 
    I think I have yet to make it to 4 years on a coupler.  Definitely could be that, but are you sure that alignment is spot on?

    Dream 'Inn III -- 2008 400 Express

  • Handymans342Handymans342 Member Posts: 10,375 ✭✭✭✭✭
  • PickleRickPickleRick Member Posts: 4,012 ✭✭✭✭✭
    https://greenville.craigslist.org/boa/d/greenville-30-ft-sea-ray-300-sundancer/7327304131.html


    This would make a little more comfortable live aboard and remedy your current issues
  • Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    If the coupler failed you would lose power to the prop. It could be damaged on the splines or loose on the flywheel.  I’d tend towards bad u-joint(s). 

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    edited June 2021
    So how are the ujoints bad on both the brand new drive and the old drive? They were both making the sound.. do you re-use ujoints? 

    As I said the noise was MUCH louder on the very top of the drive than actually on the transom. or anywhere inside the engine bay. 
  • aero3113aero3113 Member Posts: 9,044 ✭✭✭✭✭
    Wrong coupler being used? Or maybe wrong input shaft length?
    2008 330EC
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    aero3113 said:
    Wrong coupler being used? Or maybe wrong input shaft length?
    Engine was shipped directly from Mercury, with the coupler on it, so that would be a pretty big mistake. Wrong input shaft length... possible, I didn't handle any of that. All was in the mechanics hands. 
  • PickleRickPickleRick Member Posts: 4,012 ✭✭✭✭✭
    I don't think the bravo drives have different options for the u joint shafts.  Im
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    edited June 2021
    Yes, we've been through that, it is absolutely the more expensive sealed bearing, although I am leaving it in the hands of a new mechanic to figure out. 

    This is the noise that completely goes away in gear and does not appear to have any negative effects underway. Although as I've said, I've kept it on light duty this whole time because I just need the boat to get me about 5 mins out to an island.. 

    https://photos.app.goo.gl/eivrNSNvDdWNRhmq8

    https://photos.app.goo.gl/8bCdy2bQ8AkD6SMR8
  • Handymans342Handymans342 Member Posts: 10,375 ✭✭✭✭✭
    I hope your new mechanic is half as smart as Al
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    Goes away under load in the water, have not tried it up in the air. Have not inspected flappers, you can "feel" the noise if you put your hand on top of the outdrive at the very top. You cannot feel the noise inside the engine bay anywhere. 
  • LaReaLaRea Member, Moderator Posts: 7,747 mod
    Would it be worth poking around with a ten-dollar mechanic stethoscope?  
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    That's been done - loudest was the top of the out drive. Could be heard all around the transom, but nothing much from any of the engine parts inside the engine bay. 
  • Handymans342Handymans342 Member Posts: 10,375 ✭✭✭✭✭
    Pull the top off and look in
  • reneechris14reneechris14 Member Posts: 3,134 ✭✭✭✭✭
    edited June 2021
    When I did my coupler years ago I was told to run the motor with the drive off to make sure it is centered as not all couplers are perfect. Yours has been on for years now so unless something messed with it it should be ok.
    Post edited by reneechris14 on
    2005 Rinker FV342  Pawcatuck river,Ct
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    Here we go again... 


  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    The new mechanic took the time to come and listen to both the drive, where I told him it was the loudest and the transom... 

    He said the engine doesn't need to come out and this a drive problem. A carrier bearing or something like that inside the drive. 

    The question is why did the old drive and the new drive have this problem.

    Unfortunately I am 13 months into ownership of this new seacore bravo 3 drive. (sigh).

    As we have talked about for more than a year, the engine came out, the transom was redone, the transom seal was fixed and then the motor was put back in, along with the old drive. The old drive then started to make this noise, then the new drive did the same thing.

    Then after the new drive made this noise I pulled it out on my own to verify alignment. It was NOT aligned at this point and I could barely get the bar in and out. I adjusted to where it was buttery smooth in and out, but at this point the damage must have been done to the new drive.

    The mechanics who took the engine out and put it back in did NOT bend those metal tabs on the alignment bolts. The new mechanic says that the engine could have settled and this could POSSIBLY be what is going on. Keep in mind he is not saying it's 100% the problem, just a possible cause. 

    At this point he's going to take the drive off, replace the gimbal bearing (3rd in 2 years) and inspect the out drive. I have no idea what to do if it come back that the drive carrier bearings are torn up. I guess at that point it's find out how much to fix or go purchase another one from all American drives and call it a freakin day.  
  • PickleRickPickleRick Member Posts: 4,012 ✭✭✭✭✭
    edited June 2021
    I didn't know a mis adjusted alignment could take out the inner workings of the bravo, only the u joint and gimball.  That would suck to need a top housing rebuid so soon. 
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    yeah - again, it's not 100%, but he does seem to think the problem is NOT inside the engine bay (as I've been saying for a year now). 
  • aero3113aero3113 Member Posts: 9,044 ✭✭✭✭✭
    @J3ff , A loose shift fork is known to make noises. It’s on the top end so have them check that also.
    2008 330EC
  • J3ffJ3ff Member Posts: 4,096 ✭✭✭✭✭
    aero3113 said:
    @J3ff , A loose shift fork is known to make noises. It’s on the top end so have them check that also.
    I have read that too, the problem is there's a LOT of vibration going on now.. 
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