FORD 2010 F-150 v.3 - Manual (Page 395)

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.
Checking 6-speed automatic transmission fluid
The automatic transmission does not have a transmission fluid dipstick.
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.
Transmission fluid should be checked by an authorized dealer. If
required, fluid should be added by an authorized dealer.
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.
TRANSFER CASE FLUID (IF EQUIPPED)
1. Clean the filler plug.
2. Remove the filler plug and
inspect the fluid level.
DR
AIN
FI
LL
Maintenance and Specifications
395
2010 F-150 (f12)
Owners Guide, 3rd Printing
USA (fus)