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Broken Crank Position Sensor - Leave it in the bellhousing?

Discussion in 'Mondial' started by moysiuan, May 20, 2020 at 7:29 PM.

  1. moysiuan

    moysiuan Formula 3
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    Andy
    This is a new ancillary thread relating to diagnosing a poor running condition:

    While trying to remove and replace the crank position sensor on my 1988 Mondial 3.2, the sensor that is difficult to access on the front side of the engine bellhousing, the item had galvanically corroded the steel flange to the aluminum casting. The attempt to wiggle it off resulted in breaking the plastic piece, and the bottom part falling into the bellhousing. Frankly, I doubt there was any other way this could have gone, the item being in an inset in the bellousing made it impossible to lever or separate the flange from the casting, and of course there is very difficult axccess to get in there regardless.

    I know in a perfect world I would need to remove the bellhousing and fish out the broken piece. But is there any chance it can just sit inside there and do no harm, it would be mostly a plastic piece? Anyone ever done this and just left it be and deal with it the next clutch change? Can anyone make me feel better about this, or at the least raise a int of beer in my honour to wish me luck on my bellhousing removal project.

    Pic of the difficult location, the old broken one and the new one so you can see the bottom piece that went missing...

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  2. Wade

    Wade Three Time F1 World Champ
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    A similar problem happened to another here... and this was Steve's reply.

    https://www.ferrarichat.com/forum/posts/145292124/
     
  3. moysiuan

    moysiuan Formula 3
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    Interesting, obviously riskier than removing it properly through bell housing removal, but some plastic and soft metal might well do no harm...
     
  4. conan

    conan Formula Junior

    Nov 13, 2011
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    Hi, you might want to try a snake camera with a fishing hook. Not sure it will work, just an idea. They are cheap and sometimes terrible in their construction. I bought one with wifi connection since usb interface might not work well with all smart phones.
     
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  5. johnk...

    johnk... F1 Veteran
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    Jun 11, 2004
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    Crank sensors are generally a cylindrical magnet wrapped by a coil encased in plastic. Basted on the pictures in the thread referred to it would appear that the portion that broke off may contain that magnet. Check the new unit to see it the tip is magnetic. If so, then you have a magnet rolling around in the bell housing, or perhaps clinging to the flywheel.

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  6. moysiuan

    moysiuan Formula 3
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    Yes, there is a magnetic tip, and it is clear the magnet broke in half. So yes there is a magnet of about 1.5cm long encased in plastic probably clinging to something steel inside. I doubt I could fish it out, difficult access aside because of the magnetic aspect. If I left it in and it busted into peices then there would be magnetic peices flying around in there, not just falling out the bottom access slot at the bellhousing bottom. Not looking good.
     
  7. MvT

    MvT F1 Rookie
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    #7 MvT, May 23, 2020 at 2:24 AM
    Last edited: May 23, 2020 at 2:31 AM
    Ajajaj, bummer it broke off! Personally I would take it out, but I modified some things for removing the bellhousing in 1hour and put it back on in 1,5 hours. It's a relatively easy job when you have the tools for it.

    About leaving it in. The clutch itself it pretty much closed of for the part that broke off and IMHO the only thing where it can be stuck in is between the flywheel and the starter. Also there is not much room that the part can move "freely" so the initial start it will definately move. All it pretty solid materials, but it won't be a pretty noisee I think.

    I do not see a chance to take something out with a magnet knowing the space you have in there and the contents is all metal anyway. the best chance you have is via the inspecting hole to have a glance if you see the little s**ker and when you do depending on its angle thinking about a tool or electricity wire to use.

    When you take off the flywheel bellhousing you will need to replace the O-rings between the bellhousing and the transmission and a Ringnut tool is needed to be able to take the Bellhousing off.

    Edit..
    Not sure if you know BellBloke still, but he had the same issue (breaking off)
    https://www.ferrarichat.com/forum/threads/kato-cylinders-5-8-timing-issue.440107/
     
  8. moysiuan

    moysiuan Formula 3
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    Great comments, thank you. I have ordered a camerascope to see if I can see anything in there through the various access holes. Also a claw like tool which might be able to grab the thing if it is accessible. If I exhaust all the extraction options, I suspect I will take a chance, but I will cross that bridge after my new tools arrive and see how that goes.
     
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