My experience with AOD trannys has been you have to push the button to turn overdrive off or it automatically shifts into it and it does shift down no problem when you slow down and if you dont push the button you can still shift into 2nd. The AOD would work with your shifter you would just have to put a button somewhere. The only time, in my Fords with the button I use it is when coming down steep grades. Other wise it works just like any other Ford automatic (put it in 2nd and it stays there)
In stock form you simply put it in drive and it goes up through the grears and back down. The only time it does not go in and out of OD is when it disabled by pushing the button. In my f-150 (4r70w that shifts the same as an AOD) I just put it in drive unless I'm comming down a grade or towing.. The difference with Ford auto trannys is you can start out in 2nd gear if you put it in 2nd it stays there. GM or Dodges dont do that.. Your C6 should do that to.
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