The fill plug location on a 1996 Mustang automatic transmission is
on the driver's side of the transmission, near the top. However, it's important to note that
it's often difficult to access and may require removing parts to get to it. Some mechanics recommend checking the transmission fluid level through the dipstick tube instead.
Because of the difficulty and potential for mistakes, it's strongly recommended to consult a repair manual specific to your 1996 Mustang's transmission type (e.g., AOD, 4R70W) or take it to a qualified mechanic for a transmission fluid check and service. Mis-locating the plug or overfilling can damage the transmission.
