quick help

[ellococt]

so i was going to change the speedometer cable on my car today it is a 1971 plymouth scamp so i was following the old wire out through the firewall grommet and right next to the firewall the cable connects to a round tube looking thing which has a cable out the end that goes to the tranny can someone tell me what this tube does? i want to change the cable that goes from the speedometer because it is broken at the connector.

 

[pettybludart]

so i was going to change the speedometer cable on my car today it is a 1971 plymouth scamp so i was following the old wire out through the firewall grommet and right next to the firewall the cable connects to a round tube looking thing which has a cable out the end that goes to the tranny can someone tell me what this tube does? i want to change the cable that goes from the speedometer because it is broken at the connector.

Sounds to me like this tube like thingy..is your speedo cable,if it goes to the tranny(can??)