I drive a 1991 doge ram 250 with the 318 engine and 727 trans. It does not change down from third gear automatically. It will change up through all down from 2 to 1 but not from 3 to 2 I have checked the throttle linkage which was stuck in one position, I freed it off but no improvement thanks , greetings from Scotland

 

I am having a similar problem right now sometimes stays in 3rd when I come to a stop, it should just be a simple kickdown adjustment, I will be doing it tomorrow on mine and will report back with some more details for ya

 

that is another symptom, stays in third when stopping and vibrates, just manual change to stop vibrating. thanks for your help

 

Goes back to the kickdown linkage, governor malfunction, Kickdown servo band or linkage. I would check all of the linkage adjustments . After that I would change the fluid and filter

 

Not much help here, adjusted mine this afternoon, turns out I had it backwards, when I was at wide open throttle the linkage was getting pulled forward instead of pushed toward the back of the car, made the adjustment on mine and now the rear rod(vertical one) hits the back of the cylinder head(not sure if it has something to do with them being magnum heads but I doubt it) and is worse than before. So I will give it another look tonight and might just order the cable kit through bouchillion, in your case just make sure the linkage is all the way back when the throttle is fully open(check at carb and trans) sorry I couldnt be more help-kinda stuck on this one myself