<html><body>Michael- I'm not finding anything with 13TPI. I assume you are referring to part 1B3665 (#22 in GB diagram). The switch that goes in, 2H2272 was changed to 11G3062. Not sure if that part change was to UNF or just from screw terminal to clips. If they kept the same thread thru out production it must be some kind of British:<div><br></div><div>5/8 Whitworth 15.875MM 55degrees </div><div>5/8 BSF is 14TPI</div><div>5/8 BSPF (British Standard Pipe Parallel) 55degrees, 14TPI also called HSS</div><div>5/8 BSC (British Std. Cycle) fine thread</div><div>5/8 BSTP (British Standard Taper) ?</div><div><br></div><div>By the way there is one for sale on ebay for $45. Regards, Hank</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br><div class="reply-new-signature"></div><p>-----------------------------------------</p>From: "Michael Salter via Healeys" <healeys@autox.team.net><br>To: "healeys@autox.team.net"<br>Cc: <br>Sent: Wednesday August 11 2021 10:42:15AM<br>Subject: [Healeys] Another thread question<br><br>
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<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;">The inhibitor switch
which is used in overdrive gearboxes has a thread that I cannot
identify.</div>
<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;">Measuring the
outside diameter of the thread I get 0.618" ... probably 5/8"
(0.625)</div>
<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;">The TPI is 13 ...
definitely not 12 or 14.</div>
<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;">Can't find it in my
limited resources ...<br></div>
<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;">Anyone able to
identify this thread for me?</div>
<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;"><br></div>
<div class="gmail_default" style="font-family:arial, sans-serif;font-size:small;">M<br></div>
</div>
</healeys@autox.team.net></div></body></html>