FORD 2009 F-150 v.1 - Manual (Page 384)

You can check the fluid without driving if the ambient temperature is
above 50°F (10°C). However, if fluid is added at this time, an overfill
condition could result when the vehicle reaches normal operating
temperature.
The transmission fluid should be in
this range if at normal operating
temperature (150°F-170°F
[66°C-77°C]).
The transmission fluid should be in
this range if at ambient temperature
(50°F-95°F [10°C-35°C]).
High fluid level
Fluid levels above the safe range
may result in transmission failure.
An overfill condition of transmission
fluid may cause shift and/or
engagement concerns and/or
possible damage.
High fluid levels can be caused by an overheating condition.
Adjusting automatic transmission fluid levels
Before adding any fluid, make sure the correct type is used. The type of
fluid used is normally indicated on the dipstick. Refer to Maintenance
product specifications and capacities in this chapter.
Use of a non-approved automatic transmission fluid may cause
internal transmission component damage.
If necessary, add fluid in 1/2 pint (250 ml) increments through the filler
tube until the level is correct.
If an overfill occurs, excess fluid
should be removed by an authorized
dealer.
An overfill condition of
transmission fluid may cause
shift and/or engagement concerns and/or possible damage.
2009 F-150 (f12)
Owners Guide, 1st Printing
USA (fus)
Maintenance and Specifications
384