Ford 2010 F-250 Owner's Manual page 385

Maintenance and Specifications
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 handle and also in the
Maintenance Product Specifications and Capacities section 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 a qualified
technician.
An overfill condition of
transmission fluid may cause shift and/or engagement concerns
and/or possible damage.
Do not use supplemental transmission fluid additives, treatments or
cleaning agents. The use of these materials may affect transmission
operation and result in damage to internal transmission components.
385
2010 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)