Ford Aerostar 1986-1997 Repair Guide

Automatic Transmission



Fill the automatic transmission with Ford Motocraft MERCON® or Dexron®II fluid.


See Figures 1, 2 and 3

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Fig. Fig. 1: Remove the transmission fluid dipstick from the center portion of the engine compartment

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Fig. Fig. 2: When the dipstick is wiped clean, the high and low marks can be seen

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Fig. Fig. 3: Use a funnel attached to the dipstick tube to add transmission fluid

Correct automatic transmission fluid level is important for proper operation of the vehicle. Low fluid level causes transmission slippage, while overfilling can cause foaming, loss of fluid or malfunction of the transmission. Since transmission fluid expands as temperature rises, it is advisable to check the fluid level at operating temperature after about 20 miles (32 km) of driving, however, the fluid level can be checked at room temperature.

To check the fluid level, park the vehicle on a level surface and apply the parking brake. Start the engine and hold the foot brake while moving the transmission shift lever through all the gear positions, allowing sufficient time for each gear to engage. Return the shifter to the PARK position and leave the engine running.

Secure all loose clothing and remove any jewelry, then open the hood. While protecting yourself against engine heat, wipe the dipstick cap clean, then remove the dipstick. Wipe the dipstick clean then reinsert it into the tube, making sure it is fully seated. Remove the dipstick again and read the fluid level on the dipstick scale. At normal operating temperature, the level on the dipstick should be within the crosshatched area or between the arrows. At room temperature, the level should be between the middle and top hole on the dipstick.

If the vehicle was operated a long period of time at high speeds, in city traffic or hot weather, or was used to pull a trailer, to obtain an accurate reading, allow the the vehicle to cool for approximately 30 minutes before checking the fluid level.

If fluid has to be added, use a small necked funnel to add the necessary amount of Dexron® or Mecron® type fluid through the dipstick tube to bring the level up to normal. Do not bring the level above the crosshatched area on the dipstick. If overfilled, the excess transmission fluid must be removed. Once the fluid level is correct, reinsert the dipstick and make sure it is fully seated.

Do not operate the vehicle if the fluid level is at the "DO NOT DRIVE" mark on the dipstick. Serious damage to the transmission could result.


See Figures 4 through 10

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Fig. Fig. 4: Loosen and remove all the pan retainer bolts except for on one side

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Fig. Fig. 5: Once the fluid has drained out, remove the remaining bolts and lower the pan down

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Fig. Fig. 6: With the pan removed, the filter is clearly visible. Make sure the replacement filter is alike

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Fig. Fig. 7: Loosen the filter retainer bolt

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Fig. Fig. 8: Lower the filter down. Be careful, some remaining fluid may spill out

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Fig. Fig. 9: With the pan on a clean surface. remove the gasket, and clean the gasket mating surface

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Fig. Fig. 10: Remove the magnet from the pan and clean any metal particles off it

  1. Park the vehicle on a level surface and place a drip pan under the transmission to catch the fluid.
  3. Slowly loosen the pan attaching bolts. When all the bolts are loose, gradually remove all the bolts except for two at one end to allow the pan to tilt down and the fluid to drain out.
  5. When the fluid has drained from the transmission oil pan, remove the remaining mounting bolts and lower the pan. Some fluid may still be in the pan, therefore lower it carefully and pour out any remaining fluid.
  7. Thoroughly clean the pan and filter screen with suitable solvent and remove any old gasket material from the pan or transmission housing. Clean all gasket mating surfaces thoroughly, but be careful not to scratch any aluminum surfaces. Do not attempt to reuse an old pan gasket.
  9. Place a new gasket on the pan, then install the pan on the transmission. Install the pan bolts and tighten them evenly in a crisscross pattern to 8-10 ft.lbs. (11-14 Nm). Do not overtighten the pan bolts.
  11. Add three quarts of fluid to the transmission through the filler tube, then check the transmission fluid level as described earlier and add additional fluid, if necessary.