1996 Ford Aerostar Owner's Manual - Page 171

P (Park) Always come to a complete stop before you shift into P (Park). This position locks the transmission and prevents the rear wheels from turning. To securely latch the gearshift in the P (Park) position, pull it toward you, push it completely counterclockwise against the stop, and then push it toward the instrument panel. RWARNING Always set the parking brake fully and make sure the gearshift is securely latched in P (Park). RWARNING Never leave your vehicle unattended while it is running. Forced Downshifts To gain acceleration in j (Overdrive) or Drive (j position with Overdrive cancelled) when passing another vehicle, push the accelerator to the floor. The transmission will downshift to 2 (Second) gear or to 1 (First) gear at calibrated speeds. Power Braking Increasing the engine speed above idle without vehicle movement (such as holding the brake) in a forward or reverse gear causes transmission stall. NOTE: Continued operation in the stall condition can result in transmission overheat, malfunction or fluid expulsion. 190