MY girlfriend has an '85 5.0 and she is having issues with the car shifting she said that the car won't shift gears in drive she has to manually shift them. I checked the tranny fluid and it was fine. i have no clue what it is i have been told about some vacum modulator controls the shift points and that might be the problem but i don't know its an aod and i mainly work on manuals so and this stuff is new to me any help would be great thanx.