Ford 1996 Bronco Manual page 311

Continuous operation and/or extensive idling
(a delivery service as an example).
Operating in severe dust conditions.
NOTE: Use of a transmission fluid other than
specified could result in transmission
malfunction and/or failure. Refer to
"Adding automatic transmission fluid",
"Refill capacities" and "lubricant
specifications" for further information.
Checking the Automatic Transmission
Fluid
It is preferable to check the transmission fluid
level at normal operating temperature
150˚F-170˚F (66˚C-77˚C), after approximately 20
miles (32 km) of driving. However, if necessary,
you can check the fluid level without having to
drive 20 miles (32 km) to obtain a normal
operating temperature if outside temperatures
are above 50˚F (10˚C).
NOTE: If the vehicle has been operated for an
extended period at high speeds or in
city traffic during hot weather, or
pulling a trailer, the vehicle should be
turned off for about 30 minutes to
allow the fluid to cool before checking.
With the vehicle on a level surface, start the
engine and move the transmission shift selector
through all of the gear ranges allowing sufficient
time for each position to engage. Securely latch
the transmission shift selector in the Park (P)
position, fully set the parking brake and leave
the engine running.
NOTE: Vehicles equipped with the 4x4 option
must have the 4x4 shift selector in any
position other than neutral.
314