I recently used the four wheel drive to get out of out garage because of snow. I put it in neutral with my foot on the brake and put it in 4wd high. Once i got it out i turned it back off in neutral with my foot on the brake. That night it did drive over 60 mph but 1 week later it won't go over 30 mph. Whats the problem with it? Its a 1999 Expedition Eddie Bauer with the 5.4 and AWD. Please Help right away. Thank You. It has 95,000 miles and has been treated very nice.