One problem related to power train has been reported for the 1998 Mercury Mountaineer. The most recently reported issues are listed below.
While driving, the (3rd) gear went out. The transmission was checked and pieces of the gear was found. The transmission was replaced at an independent transmission mechanic (northeastern transmission). The parts were taken to the dealership, however they refused to inspected the parts. The consumer then contacted the manufacturer, but they were not willing to assist. (northern ohio automotive, 7513 tyler blvd; mentor OH 44060, 440 942 2524.