SV Speedometer input 'screw' size?

[Scotty]

Hi folks!

Anyone know what the size of the outside 'screw' on the back of the Speedo that the cable screws onto is?

I picked up a set of replica Smiths gauges from India (that Speedo 'screw-on' is M18x1.5) and I'd ideally like to adapt it to the speedo cable I got. I'll post a pic when I'm done and do a review of them just so others have an idea.

For those who are wondering why I don't just keep the Jaegers, well, mine are mismatched, some are damaged on the face and the SV speedo I have is damaged, plus these are cheap and I'm not expecting miracles, just something that will work. Plus, my daily driver is currently on a tight budget.

I've already installed the other gauges outside of the Speedo and Tach which I should get on Tuesday and so far, they're pretty damn impressive for the price.

 

[Green67Alpine]

I dug out an old Jaeger speedo and the best measurements I could come up with is 12mm 1.0 thread. Sounds not quite right but that's what I came up with. Good luck.
Tom j

 

[puff4]

I haven’t checked, but there’s a good chance they are BA/BS threads. If I get time I’ll pull one from my spares boxes and check, but Smiths, Jaeger, Lucas and SU were among the last to convert from Whitworth-era fasteners to NF/NC sizing.