Ford Town Car 2006 Owner's Manual page 256

Maintenance and Specifications
Low fluid level
Do not drive the vehicle if the fluid
level is at the bottom of the dipstick
and the ambient temperature is
above 50°F (10°C).
Correct fluid level
The transmission fluid should be checked at normal operating
temperature 150°F-170°F (66°C-77°C) on a level surface. The normal
operating temperature can be reached after approximately 20 miles
(30 km) of driving.
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.
256
2008 Town Car (tow)
Owners Guide (post-2002-fmt)
USA (fus)