One problem related to automatic transmission torque converter has been reported for the 1998 Ford Ranger. The most recently reported issues are listed below.
The transmision torque converter seems to whine from aprox. 2,500 rpm until gear shift when accelerating. When overdrive is disengaged above 50mph the transmision slams. The wheel lug nuts were not torqued correctly upon delivery of vehicle resulting in 1 elongated rim. Air conditioning has been returned to dealer 3 times. Told nothing was wrong with the system that it was within "Ford" specs, yet miraculously it is cold again for approx 1-2 months.