Why it will not go into gear when the motor is cold on 1990 Ford Aerostar

Everytime I try to start the engine when the motor is cold, it will not move when I put it in drive or reverse

Asked by for the 1990 Ford Aerostar
When was the last time the trans filter & fluid been changed?
2 more answers , 1 more comment
Sounds like an internal transmission problem.
well duh!
Dont be scared of the [INTERNAL]word..The trans. filter is [INTERNAL]but very very simple to replace..Parts and fluid will cost about 30.00.A fifteen min. job.IF THEY KNOW WHAT THEY R..DOING..