[FearNoEvo]

Don't forget, searching google to find good posts on the JJ can be a hell of a lot easier than searching the JJ for good threads on the JJ

I typed this into google:

"triumph oil pressure switch thread size"

Which lead me to this:

http://www.jockeyjournal.com/forum/showthread.php?t=60377

Which lead me to this:

http://www.jockeyjournal.com/forum/showpost.php?p=546740&postcount=5

 

[FearNoEvo]

You can make a take off of the thread using body filler and a bit of care. Then you can measure the exact pitch of thread. What I gathered from the thread I posted, is that there are 3 possible pitches depending on the exact year of your side cover, 26, 27, 28. Determining the correct pitch will get you well on your way to finding the right fitting.