One problem related to transmission not engage has been reported for the 1999 Ford Expedition. The most recently reported issues are listed below.
When vehicle is put into reverse it is not engaging. You must use the accelerator to go anywhere and then the front end feels as if it is stuck on something and reverses extremely hard and makes a very loud screeching noise. Dealer says there is nothing wrong and cannot do anything unless the problem occurs when at the dealership. I took it directly to them after the problem occured this last time.