Round speedometer cable

[Brianfrench65]

I had to replace my speedometer cable, because the end that connects at the drive shaft fell apart. The new cable will not screw in all the way, on the round speedometer end. So, I purchased another cable, from a different supplier, and the same thing, it will not thread all the way into the round speedometer. I have 3) round speedometers, and the fit is the same with all of them.

Has anyone had the same experience? How did you remedy the situation?

It looks to me, that it is an 3/4"-20 thread - is that correct?

Thank you very much for any suggestions;