How far off is it? Most Fords have an adjuster wheel that can compensate for the cable stretching a little. If it is showing R when it is in park, for example, just take the panel above the floormat off (below the steering wheel) driver's side and there is an adjuster behind there- you should be able to turn it with your fingers and set it back right. If it is off big time there may be another issue with it.