speedo cable problems

have a 67 barracuda with 904 transmission. Speedo has not worked since i bought the car. When I unscrewed the cable at the tranny there was no actual cable running into speedo gear housing?
Recently bought a new cable and tried to intstall it but it did not work... It was difficult to insert at both the speedo and it felt like i almost had to jam it in the speedo gear housing to insert it. When I took it for a test drive I still did not have any speedo reading? When i pulled it from the housing it looked like it had broken/sheared off in the housing... Any idea what i am doing wrong? Any thoughts or advice are welcome. Thanks.