What is the name of transmission that in an automatic 4x4 1990 Ford F150 5.0?
The 1990 Ford F-150 with a 5.0L engine and automatic 4x4 transmission likely used either a 4R70W or an E4OD transmission. The 4R70W was more common in later years of the decade, but E4OD was used earlier. There's no way to know for certain without checking the truck's documentation or the transmission itself.