How to separate the dome from the gear !
  • First, the plastic medallion is chiselled away.

    The medallion is removed, as well as the cardboard backing. This exposes the top of the "dome".

    The next phase, and success of the whole operation revolved around devising the proper "tool" to push against the dome. Indeed, the top of the dome is not flat - it is "domed"! Pushing on the upper edge would in effect expand it and make pressing it out impossible. There's a fine edge by the outer perimeter of the dome. That's where one has to push.

    Finding a suitable device proved to be a challenge. I settled on cutting up a fan pulley. It was the perfect size and diameter. Here's a view of the cut-up pulley, showing where it will fit.

    You can see the tight dimensions - the "Special Tool" must fit INSIDE
    the aluminium gear, as well !

    Finally, the fan spacer will serve as a handy object for the press to act on.

    Now, the gear is placed on the press.

    And the "special tool " put in place.
    (Picture is wrong. It should show the fan spacer sitting on top of the Special Tool)

    Start pumping the press handle and be ready for an explosion;
    the two parts are welded together by corrosion! Eventually, they WILL pop apart. Noisily.

    Now all components can be restored, cleaned, polished, anodized, or whatever...
    but that is another story!

    Please click HERE to go back to beginning of this article.

    Please click HERE to go back to the Tech page.

    John