Have a Sunliner -56 with automatic transmission, the plastic gear has come loose from speedometer wire, how is that attatched to the wire????
Glued or what?
The same thing happened to my 59 corvette repop cable. I would never use them again, it's a big job to take the dash out to replace it. Do your self a favor and get rid of it.
If you are talking about the plastic coupling at the top end of an original speedo cable, it can be difficult to re-install the metal clip into the coupling. The metal clip must be forced down around the outside surface of the cable while the coupling is attached. The metal clip is slightly bent near the bottom half of the clip so you know when to stop pushing down. It is a tight fit.
The repro cables are designed to be used without the coupling and clip.