It seems that my tranny is headed south. When in overdrive it free revs and won't go. If I click the overdrive off it drives fine as long as I don't want to go fast. Once I'm up to speed I can engage the overdrive and it works fine as long as I don't let it down shift. I'm hoping it's something simple. I'm sure someone on here knows something about transmissions. Due to financial concerns I'll probably have to repair it myself. I've never been in an auto tranny before so any help would be appreciated. BTW, it's a 92 E250 with an E4OD and 295,000 miles. I was told the tranny was rebuilt once by the original owner.