AW4 kickdown problem

1987 4.0, AW4 Stock Engine and trans...

The transmission does not want to downshift on a hill. I have to bury the skinny pedal into the carpet and let the engine lug to 1500 RPM before I get a downshift. I can downshift it manually into third and it will pull the steepest of Instertate highway hills just fine.

I have checked the TPS sensor adjustment and have it within 0.02 volts of perfect. There are no dead spots in the sweep. The FSM says to verify the throttle plate is wide open with the accelerator pedal on the floor; it is.

All AT cars I have serviced in the past had a mechanical linkage from the throttle to the transmission to control this downshift. It was usually referred to as the kickdown linkage or cable. Following the FSM, I found there is a Line Pressure Cable, also called a Throttle Cable, in the same FSM. TThis appears to be the kickdown calbe.

The adjustment procedure for this cable is:
The FSM shows a picture of the trans end of the cable, with a self-adjusting mechanism at the transmission end.

The adjustment is simple enough, but it does not fix my problem. I suspect this self-adjusting mechanism on the cable may be defective.

Has anybody needed to replace their transmission to throttle cable for a similar problem?

TIA....

Mine does the same thing. I've adjusted the throttle cable and it get a little better, but still won't downshift unless I'm going 40 or below. Once I hit 40 it upshifts no matter what pretty much. Load seems to have almost nothing to do with it.