Ford 1999 Wagon-Econoline Owner's Manual page 192

Capacities and specifications
7
Ensure the correct automatic transmission fluid is used for a specific
application. Check the container to verify the fluid is MERCON
approved. Transmission fluid requirements are indicated on the dipstick
handle. Refer to the maintenance guide and or service guide.
Do NOT use any non-approved automatic transmission fluid for an
application specifying MERCON . Use of a non-approved fluid may cause
internal transmission component damage.
8
Indicates only approximate dry-fill capacity. Some applications may
vary based on cooler size and if equipped with an in-tank cooler. The
amount of transmission fluid and fluid level should be set by the
indication on the dipstick's normal operating range.
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