Hi there
So you checked your dipstick and there was debris in it?
What kind of debris, metal pieces?
Also you cant get out of overdrive since the switch on top of the gear selector is for O/D off?
Also, i have had 8 transmissions in my 1999 windstar with the first one replaced at 14000km. Most people have had many many many many problems with windstar transmission at early milage. Since you are going to ford they will probably check your transmission and probably change the fluid. If you keep your windstar have the transmission fluid changed once a year to prolong the life of your tranny, since they are notorious for failing. | 
