My experience with those type of detent rods and cables is that when taken OFF completely the tranny shifts at the lowest possible mph. Then when tightened up all the way the tranny thinks you have the pedal depressed to the floor..ie it shifts at the highest possible speed.
So I would look to loosening the cable..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist