1998 caravan tranny acting up

just bought a 98 caravan with the 3.0 and a 3 speed tranny. the tranny wasnt shifting rite at all so took it to aamco and they adjusted the tv cable and it shifted 100 times better but i think they had it off a fractiuon.. so i moved it a hair and it seems a little better but seems it could use another fraction.. my question is.. are the tv cable adjustments that sensitive that moving it only 1/8th to 1/4 inch make a dramatic dif.

it was shiffting with a slight slip after got it back from aamco i moved it like i said about a 1/4 inch and now it is waiting to long to shift into 3rd..