Automatic Transmission: The automatic transmission fluid (ATF) fill location is usually on the side of the transmission itself. It's often a small plug or cap that might require a special tool or socket. You cannot simply add fluid through the dipstick tube (if there even is one that is accessible). You will need to consult your owner's manual for the exact location and procedure. Improper filling can damage the transmission.
Manual Transmission: Manual transmissions typically have a separate fill plug on the transmission case. Again, your owner's manual is crucial for locating this plug and understanding the proper procedure. It also specifies the type and quantity of gear oil to use.
In short: Do not attempt to fill the transmission fluid without first consulting your owner's manual. It's the only way to be certain of the correct location and procedure, preventing potential damage to your vehicle. The year and model of your Aerostar will also affect the exact location and process.
