Throttle valve/Kick down thingy

[68CHARGER6]

In the process of elimination of discovering why I have no overdrive in my 93 4x4 auto, I discovered that the cable operation that goes to the little arm on the side of the tranny is buggered up. The arm does not come all the way back after the throttle is pushed down. So I am going to replace this cable as soon as figure out what its called. But I am wondering, how do you adjust this? Also, should I add a return spring to it to help out? Could this be a reason as to why I have no overdrive? Besides the tps, what else could it be? I am just trying to check everything before dropping a couple grand on a new tranny. Thanks for any help.