Checking fluid level on the 4R70W Auto

Checking automatic transmission fluid

Automatic transmission fluid expands when warmed. To obtain an accurate fluid check, drive the vehicle until it is at normal operating temperature (approximately 20 miles). 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 fluid to cool before checking.

1. Drive the vehicle 20 miles or until it reaches normal operating temperature.
2. Park the vehicle on a level surface and engage the parking brake.
3. With the parking brake engaged and your foot on the brake pedal, start the engine and move the gearshift lever through all of the gear ranges. Allow sufficient time for each gear to engage.
4. Latch the gearshift lever in P (Park) and leave the engine running.
5. Remove the dipstick, wiping it clean with a clean, dry lint free rag.
6. Install the dipstick making sure it is fully seated in the filler tube.
7. Remove the dipstick and inspect the fluid level. The fluid should be in the designated area for normal operating temperature or ambient temperature.

Low fluid level

Do not drive the vehicle if the fluid level is at the bottom of the dipstick and the ambient temperature is above 10C (50F). Correct fluid level The transmission fluid should be checked at normal operating temperature 150F-170F on a level surface. The normal operating temperature can be reached after approximately 20 miles of driving.
You can check the fluid without driving if the ambient temperature is above 50F. However, if fluid is added at this time, an overfill condition could result when the vehicle reaches normal operating temperature. The transmission fluid should be in this range if at normal operating temperature (150F-170F). The transmission fluid should be in this range if at ambient temperature 50F-95F.

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 and also in the Lubricant specifications section in the Capacities and specifications chapter.
Motorcraft MERCON V ATF Capacity is 13.9 quarts.
Use of a non-approved automatic transmission fluid may cause internal transmission component damage. If necessary, add fluid in 1/2 pint 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.

An ideal temperature for the transmission to run at is in the 160 - 180 *F range.
For every 20* of increase in temp above 170*F the life of the fluid is cut in half.
This is why an auxillary transmission cooler is a must.


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