jhofmannjhofmann Member Posts: 430 ✭✭✭

My Bravo 3 outdrive vibrates when trimmed in. I thought it may be u-joint related until I had to replace the outdrive and still had the same vibration. This is my first Bravo series outdrive, is this normal?


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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭

    You chould not be getting vibrations.  A few things to check:

    * The props need to be clocked to each other when installed.

    * Are the front and rear props the same pitch (they must be)

    * Engine alignment to outdrive - verify

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    TikiHut2TikiHut2 Member Posts: 1,431 ✭✭✭✭✭
    edited August 2014

    I hate to be a broken record on this topic lately but this sounds like ANOTHER bad O/D alignment or failing motor mounts. Can't think of any other cause when the drive is trimmed in/out that'd cause any noise on a new drive. Many members have recently posted that they've found their alignment to be way off (even after paying a mech to check it) causing hard to discern vibration, noise and eventual coupler failure. 

    Irregardless of what the mechanic claims, if I'd just purchased a new drive I'd like to literally see him insert and extract the alignment tool with two fingers on each 90* point of crank rotation. It's not hard but there's a perception that if they can cram/hammer it in/out then it's close enough. NOT!

    Considering that Merc claims this should be an annual inspection the good news is that this is really pretty easy to do. The tool is an ebay item for $30ish. There are youtube vids on removing the drive and raising/lowering the motor mounts is simple if you lift the front of the engine a bit to ease the load on the mounts. Adjust up/down equally on each fwd mount until you can literally insert/extract the alignment tool with two fingers. Rotate the crank pulley 90* and check again,  continue until you get the same ease all 360*. Your drive/engine will be happy you did.

    With the drive off I did this with a helper in under 30mins. My O/D has NEVER run so smooth. Unfortunately this was after no less than three people had been paid to do it but, being lazy hadn't done it thoroughly and ruined my coupler. 

    Sorry about your O/D but I'd certainly have it checked and don't accept anything less than perfection for your new drive. Mike

    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
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    jhofmannjhofmann Member Posts: 430 ✭✭✭

    The replacement outdrive a used newer style. When I replaced the gimbal bearing, I used the alignment tool and remember It went in, and came out a little hard, not with 2 fingers for sure. I thought as long as it went in, it was okay. I will have to adjust it likeTikiHut2 described. Thanks all.

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