I'd simulate the bend without inserting. Then see if the bending is causing the cable to pull from the gear. I'm assuming you have the driver gear installed in the transmission and the driven gear is matching up.
The driven gear was not engaging with the drive gear in the tranny. I ordered the "blue" 16 tooth gear seen here:
http://www.transmissioncenter.org/Ford_Speedometer_Gears.htm
and the speedo works, however, it is off by about 10 mph and the calculators I have found say I need a 17 or 19 tooth driven gear depending on what gear I have in the tranny either 7, 8, or 9 tooth. Does anyone know if more teeth on the driven gear means a larger diameter? I would need it to be long the blue one I have or to be a larger diameter.