Have a small problem with my 66 electra 401 with the th400 gearbox. When i kickdown between 2nd and 3rd gear I get a vibration in the car. once the third gear is in and I ease on the throttle the vibration stops. When I drive "normal" it changes gears so smooth you can barely feel it. And if Im running at the same topspeed without the kickdown there is no vibration, so its only when I kickdown. Suggestions anybody?
