Lower unit trim tab/anode broken bolt

Discussion in 'Outboard Maintenance' started by jmrodandgun, Feb 23, 2014.

  1. jmrodandgun

    jmrodandgun Well-Known Member

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    I have a seized and broken bolt where the trim tab anode use to be on a yamaha 25. Getting a drill in there to drill it out is a pain without removing the prop shaft. I tried to drill it out as best as I could but the stainless bolt just forces the bit into the softer aluminum. Are there any known tricks to get it out without taking everything apart to get it in a drill press?

    I've tried drifting it out and using extractors with no success. I would rather not drill the whole thing then have to fill in material but I'm not seeing another option.

    I think I know the answer to my questions but I figured I would ask in case there is something I am overlooking.
     
  2. AfterHours2

    AfterHours2 Stripper in my own Mind!

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    Other than using an angled drill, your method is spot on. Center punch the bolt, drill and use an ez out. Stainless is pretty tough but the angled drill may give you the clearance you need above the prop shaft. Good luck..
     

  3. jmrodandgun

    jmrodandgun Well-Known Member

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    Pulled the all the gears out of the lower last night. Going to have to put it in a drill press and drill the whole thing out. Then weld up the hole and drill and tap it all over again.

    We came up with an idea of drilling two new smaller holes in the lower unit and then slotting the trim anode for adjustment. This way you would just bypass the factory bolt hole. I opted to pull the gears and drill/Weld the hole because I have the tooling to do it but if you were in a pinch, adding to small bolt holes is easy and requires no special tools or skill.
     
  4. Brett

    Brett > PRO STAFF <

    A neighbor had the bolt holding the anode/tab shear.
    His solution was to attach a block anode to the transom bracket
    and installed an after market foil with adjustable tabs ons it.
    Left the sheared bolt in place, adjusted the tabs on the foil, done.
     
  5. jmrodandgun

    jmrodandgun Well-Known Member

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    I have a Permatrim that keeps it going straight for the most part. I still experience a lot of torque steer so I figured I would just fix it the right way. If I didn't have a drill press and a high frequency box I would probably bolt something onto the lower unit and be done with it. It doesn't really cost me anything except time.

    I thought maybe there would be more interest. Running in skinny water will break something at some point, I figured this would be a common issue around here.

    Now that I've got it all finished, I can say it doesn't really require any special skill except welding aluminum, which a shop will do for you for cheap once you have it drilled out. I can go through how to do it if anyone is interested but in reality it's probably more cost/time effective to drop it off at your local prop shop.