New to this site....My wife has a 2006 Ford Explorer 2WD base model. When we shift into reverse there is a few second delay followed by a hard shift into reverse. The vehicle makes a loud noise when shifting into reverse and the vehicle feels like it rocks. The vehicle shifts fine in normal driving conditions (automatic). We have found that if we depress the brake pedal hard almost to he floor, the shifting into reverse is fine with no sound and no problem. Any idea what this is?