One problem related to front suspension shock absorber has been reported for the 1999 Ford Explorer. The most recently reported issues are listed below.
When I had the firestone tires replaced, the mechanoc showed me the shocks-the driver side rear was badly damaged, the passenger rear was damaged, but not as bad as the driver side. The front shocks were not damaged. Interesting that (a)Ford Explorer(b)rear left shock completely blown (c)rear passenger shock damaged but not as bad as driver side (d)front shocks not damaged (e)I believe there have been more problems with Ford Explorer firesstone tires on the driver side rear than any other location. Design defect by Ford?.