speedometer cable to Trans

[Assault]

Hello,

About two weeks ago my speed gauge went out while I was driving on the highway, it started to sputter then just lied flat. However the next day on the highway it sputtered to 10mph then promptly died again and hasn't moved since.

This one has me baffled. My speedometer cable and instrument cluster work, we hooked a drill up to the cable end that connect to the trans and the cable went to 25mph. However, when we connect the cable to the transmission the speed needle does not move at all. We believe it to be the part that the speedometer cable connect into, which that then connect into the transmission itself. What is that part called?

It would be like this Speedometer cable + (housing that hold the cable) + transmission

Thank you!