One problem related to sway bar has been reported for the 1998 Lincoln Navigator. The most recently reported issues are listed below.
Vehicle was going 35-40mph and the front end started violently shaking due to tie rod breaking. Vehicle was very hard to control at a low speed due to wheels locking in a turning position with the steering wheel still spinning. Vehicle was just in for repair a week before to replace the sway bar. Dealer notified. The consumer stated that the service manager at dealer stated that they have had similar problems with the Navigator.