Masthead sheave pin removal

  • January 21, 2021 12:38 AM
    Message # 9886415

    Can anyone share the secret with me on how to remove the stainless steel pins from the masthead? I am trying to remove and replace the sheaves in the masthead. There are two sets of three sheaves rotating on a stainless steel tubular axis. I have removed the cover plates but I cannot come up with any way to get a grip of the stainless steel pin to extract it. It is cut flush with the mast profile (on an angle) so there is no lip to get any pliers on to and I am not able to rotate it. There does not appear to be any threads or recesses in the internal bore of the pipe so nothing to hang on to. The pins are in a captive hole, there is no access from the other side and they cannot be driven/punched through… It has me beat.

    I have been up there about four times in the last two months and I drench the entire area with a spray on commercial penetrating release agent.

    Not making it easier is that I really had no intentions of lowering the mast but would like to get this done with the mast standing.  I searched the forum but this issue does not appear to have been raised by anyone else. Do they just move freely and are easily extracted on other people’s boats? Advice would be much appreciated.

    1 file
  • January 31, 2021 8:45 PM
    Reply # 10052203 on 9886415

    Ben,  The easy way is to drill a hole on the opposite side of the mast in line with the axle pin of the sheave.  Then use a small punch to drive the pin out of the open side.  Then you can use a vise grip on the exposed pin and rotate it out.  Easy solution since I have done it many times before.  Bud

  • January 31, 2021 11:17 PM
    Reply # 10052316 on 9886415

    Thanks Bud,

    I appreciate your feedback and like your optimism.

    I just wanted to check with you where exactly do you drill this hole in relation to the sheave axle pin. Probably not the end of the world but I would like to avoid a bunch of unnecessary holes. As the sheave pin is a hollow tube do you drill it so the punch will align with the wall thickness of the axle pin (so offset from the centre line), or is the axle pin welded shut at the captive end so one can drill on the centre line and knock it out nice and square?



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