One problem related to rear suspension leaf spring shackle has been reported for the 1998 Ford F-150. The most recently reported issues are listed below.
The contact owns a 1998 Ford F-150. While driving approximately 15 mph, the contact heard a snapping sound from the rear of the vehicle. After coming to a stop the contact inspected the vehicle and noticed that the bracket that connected to the leaf spring on the rear passenger side was fractured. The vehicle was not taken to the dealer for diagnostics. The vehicle was not repaired. The approximate mileage was 146,000. Updated 5/11/12 the shackle assembly needed to be replaced. Updated 05/15/12.