Ford Aerostar Engine Hesitate

I Has The Transmission Fluid Changed, And Ever Since The Van Hesitates Terribly When Shifting Gears And Slips Out Of Gear When Driving It....

I Have Replaced O2 Sensor,distr. Cap, Plugs, Wires, Fuel Filter,ignition Coil, And When You Take Off In Drive It Still Has A Hesitation At...

This Is An 1993 Aerostar Xl With 202000 (true) Mileage; Auto Trans 4.0 L Big V6; All Power Equip. Came With Heavy Duty Trailer Pkg. Vehicle...