Ford F-250 Owner's Manual page 392

Maintenance and Specifications
TRANSMISSION FLUID
Checking automatic transmission fluid (if equipped)
Refer to your scheduled maintenance information for scheduled
intervals for fluid checks and changes. Your transmission does not
consume fluid. However, the fluid level should be checked if the
transmission is not working properly, i.e., if the transmission slips or
shifts slowly or if you notice some sign of fluid leakage.
Automatic transmission fluid expands when warmed. To obtain an
accurate fluid check, drive the vehicle until it is at normal operating
temperature (approximately 20 miles [30 km]). Verify that the
transmission fluid temperature gauge, located on the instrument cluster,
is within normal range.
1. Drive the vehicle 20 miles (30 km) or until it reaches normal operating
temperature.
2. Park the vehicle on a level surface and engage the parking brake.
3. With the parking brake engaged and your foot on the brake pedal,
start the engine and move the gearshift lever through all of the gear
ranges. Allow sufficient time for each gear to engage.
4. Latch the gearshift lever in P (Park) and leave the engine running.
5. Remove the dipstick, wiping it clean with a clean, dry lint free rag. If
necessary, refer to Identifying components in the engine compartment
in this chapter for the location of the dipstick.
6. Install the dipstick making sure it is fully seated in the filler tube.
7. Remove the dipstick and inspect the fluid level. The fluid should be in
the designated area for normal operating temperature or ambient
temperature.
Your vehicle is equipped with one of the following dipsticks.
392
2011 F-250/350/450/550 (f23)
Owners Guide, 3rd Printing
USA (fus)