1997 Ford F150 Owner Guide 1st Printing - Page 173

Maintenance and care Before adding any fluid, make sure the correct type will be used. This information is indicated on the dipstick. Do not drive the vehicle if the fluid level is below the bottom hole on the blade type dipstick (4R70W transmission) or below the COLD area on the bullet type dipstick (E4OD transmission) and outside temperatures are above 10°C (50°F). Your vehicle does not use up transmission fluid. However, it is recommended that you check the transmission fluid at least twice a year. 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. It is preferable to check the transmission fluid level at normal operating temperature, after approximately 32 km (20 miles) of driving. However, you can check the fluid level without driving to obtain a normal operating temperature if the outside temperature is above 10°C (50°F). If your vehicle has been operated for an extended period at high speeds, 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. 174