FORD 1998 E-150 - Manual (Page 66)

If your vehicle gets stuck in mud or snow it may be rocked out by
shifting from forward and reverse gears in a steady pattern. Press lightly
on the accelerator in each gear.
Do not rock the vehicle for more than a few minutes. The
transmission and tires may be damaged or the engine may
overheat.
Always set the parking brake fully and make sure the gearshift is
latched in P (Park). Turn off the ignition whenever you leave
your vehicle.
Driving with a 4–speed automatic transmission
Understanding gearshift positions
Pull the gearshift lever towards you and downward to move the
automatic gearshift.
Hold the brake pedal down while you move the gearshift lever
from position to position. If you do not hold the brake pedal
down, your vehicle may move unexpectedly and injure someone.
P (Park)
Always come to a complete stop
before shifting into P (Park). Make
sure the gearshift is securely latched
in P (Park).
R (Reverse)
With the gearshift in R (Reverse),
the vehicle will move backward.
Always come to a complete stop
before shifting into and out of R
(Reverse).
N (Neutral)
With the gearshift in N (Neutral),
the vehicle can be started and is
free to roll. Hold the brake pedal
down while in this gear.
Driving
66