"Joe" > wrote in message
ups.com...
>I have a 1972 Ford Mustang, 351C-4V, 4-speed toploader, Hurst shifter.
> The speedometer does not work (at all) so I replaced the speedometer
> cable and reused the cable driven gear inserted into the extension
> housing. Still doesn't work. I can feel the output shaft in the
> extension housing with my finger through the speedo-gear hole. I can't
> feel the drive gear on the output shaft. Is it possible that it broke
> off and is in the bottom of the extension housing? Could such a gear
> (plastic) just break off? If so, what's the best way to replace it
> now? Does the whole transmission have to be removed or is it possible
> to somehow remove the extension housing to expose the output shaft?
>

I don't think you have an internal speedometer drive gear problem. The
teeth on the internal speedometer drive gear run almost parallel with the
sides of the gear. Look at the gears in these pictures.
http://www.4speedtoploaders.com/shop...target=d9.html

Although I've only removed the tail shafts after I have removed the entire
transmission from the car, I suppose it could be removed while the
transmission is still bolted to the engine in the car.
Are you sure the speedometer cable is not turning? Are you certain it is
inserted all the way into the back of the speedometer? That can be a real
bitch sometimes. I would confirm these two items before I pulled the tail
shaft.