1996 Ford Thunderbird Owner's Manual - Page 259

With the vehicle on a level surface, start the engine and, while fully applying the brake pedal, 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 P (Park) position, fully set the parking brake and leave the engine running. NOTE: Your vehicle should not be driven if the fluid level is below the low cold reading on the dipstick. Wipe off the dipstick cap, pull the dipstick out and wipe the indicator end clean. Put the dipstick back into the filler tube and make sure it is fully seated. Pull the dipstick out and read the fluid level. When checking fluid at normal operating temperature 150˚F-170˚F (66˚C-77˚C), the fluid level should be within the hot notched area on the dipstick. When the vehicle has not been driven, and the fluid is at room temperature 50˚F-95˚F (10˚C-35˚C), the fluid level should be within the cold notched area. 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. Adding Automatic Transmission Fluid Before adding any fluid, be sure that the correct type will be used. Use only MERCON fluid. Add fluid in 1/2 pint (.25L) increments through the filler tube to bring the level to the correct area on the dipstick. DO NOT OVERFILL. If the level is above the top hole on the dipstick, excess fluid should be removed by a qualified technician. 257