Speedo Gear

[Vintageracer]

I was driving FHP #432 today when the speedometer needle to ONE big jump and quit. Upon investigation I have found that the upper Vascar cable has taken a dump. I have replaced the speedometer cable and still no speedometer. Upon inspection I have determined that the "sudden" departure of the upper cable also destroyed the speedo gear on the output shaft on the transmission. I am not sure if this gear is also plastic however I do know that this gear is not there. Stick you finger in the transmission and there is no gear. The cable speed gear is fine.

I think I know the answer to this question however here it goes! Do I have to pull the transmission to replace the speedo gear on the tailshaft or can this be replace from under the car on my lift?

Thanks for the help!