Bravo3 Help with separating the leg.

Discussion in 'Gas Engines/Drives/Transmissions/Props' started by William Miller, Apr 2, 2020.

  1. William Miller

    William Miller Member

    228
    Mar 16, 2007
    Darnestown, Maryland
    290 AJ
    Twin Mercruiser 300 hp Bravo III
    HELP! Bravo III

    I have replaced the lower drive shaft seals on both out-drives but I can't get one separated.
    The first one came right apart after taking out the 6 nuts and 2 bolts.
    This one: I can only get a slight crack at the seam.
    I think the shaft coupler connecting the upper and lower vertical shafts might be stuck together.

    I'm wondering if the shaft in the top section is drilled thru. (Or hollow?)
    Meaning: should I take off the top cap and maybe I can insert a steel rod in there and drive the bottom shaft down.

    I have to imagine there is a back door way as this must have happened before!

    By the way. I modified my engine stand to hold the outdrive.
    It cost me:
    5' length of 1" black gas pipe (Cut in half).
    6' length of 5/8" all thread, 4 nuts and washers.
    At some point I'll put some padding on it (After I repaint the drives.)


    outdrive.jpg
     
  2. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    There’s a hole 3-4” to the left of the blue strap in your picture. It’s a actually on the upper housing.
    Remove the bolt from inside the hole.
    That’ll separate the drive.
     
  3. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Here’s a photo
    DA367A67-9C96-4524-AB8F-92A261489FD6.png
     
  4. William Miller

    William Miller Member

    228
    Mar 16, 2007
    Darnestown, Maryland
    290 AJ
    Twin Mercruiser 300 hp Bravo III
    That one is out.
    It allows you to get the anode off so you can get to the second bolt that goes up from the bottom.
     
  5. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Ok. So 6 nuts removed and the one under the anode and it still won’t separate?

    The shafts are solid. The coupler is the hollow piece, it has a stop in the middle of it. If it’s jammed, maybe try shifting in and out of gear or just rotating the props while you lift off the upper.

    I use a come-a-long anchored to the ceiling joists to pull up on the upper while the lower sits in the stand. It usually needs a few whacks with a rubber mallet to get them to separate.
     
  6. William Miller

    William Miller Member

    228
    Mar 16, 2007
    Darnestown, Maryland
    290 AJ
    Twin Mercruiser 300 hp Bravo III
    Looking at the other drive, the upper shaft is in fact hallow.
    But that wasn't the problem.
    I found that at the front of the drive the casting has a wedge shaped point that a 2x4 fits in. I cut another into a wedge shape.
    I was able to get them to slowly separate using a BFH driving the wedges in alternately.
    Also used some composite shims once the crack started to finally get bigger.

    The shaft came out clean. It was just one stud that corroded solid into the hole in the lower part.

    Bottom picture of the twins in the corner with new seals and ready for paint!

    Epos4 thanks for your support.

    Ill start another thread with pictures on the seal replacement.
    outdrive wedge.jpg

    outdrive crack.jpg

    bolt corrosion.jpg

    outdrive twins.jpg
     
  7. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Your welcome.

    FYI I’m in salt water and I split the drive every year as part of my winter service.
    I always find a few barnacles inside the water passageway in the lower unit.

    I have part numbers for those o-rings that seal the upper to lower unit if needed.
     
  8. William Miller

    William Miller Member

    228
    Mar 16, 2007
    Darnestown, Maryland
    290 AJ
    Twin Mercruiser 300 hp Bravo III
    I bought the boat new in 2007.
    It has lived on a lift until last year.
    I have pulled the drives off once to check the bellows which were like new at the time.
    I pulled the engines to overhaul them along with the drives.
    I will be doing a full bellows kit on both before putting the drives back on.
    The prop shaft seals worried me so i just replaced them.
    The seals looked ok. I destroyed them when i pulled the out and found that inside the outer casing which is stainless. The two seals each have some normal steel in them which where totally disintegrated.

    I was pretty disapointed seeing that . I'm glad I caught it before it caused a leak.
    I wish i spent the money on the seal removal tool. That part took some time and made a mess,
     

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