One problem related to transmission not engage has been reported for the 2004 Ford F-150. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford F-150 based on all problems reported for the 2004 F-150.
Started my truck as usual to go to work, put it in reverse and it was like I put it in neutral, no engagement at all. Glad I wasn't in a situation when this happened that could have put myself or someone else in danger. Ford knows they have a problem, it is wide spread. Sure my truck has 124000 miles on it but the transmission malfunction light has been going on and off for the last 70000 miles and the dealer said they could not find any trouble codes or malfunctions during this period. I can rev my motor to about 2000 rpm and it will finally gently start to roll into reverse but my failsafe mode engages, check engine light comes on and the motor stumbles badly until I put the vehicle in drive gear and go about 2 miles at which time the failsafe mode goes off and it smoothes out. For the most part my vehicle has been dealer maintained.