Three problems related to differential unit have been reported for the 1999 Ford Explorer. The most recently reported issues are listed below.
In my 99 Ford Explorer 4x4, the front differential failed costing $2500 in damages. Although there was no accident the vehicle was unsafe to drive and the 4x4 system was not operating. We had no idea , the dealer caught it during a service check.
Noise is coming from the differential while driving. Dealer was notified. The consumer feels that there is a design flaw in the front differential unit. The unit should not have failed so early in the life of the vehicle and after being used only sparingly. The noise still can be heard even after the repairs.
The planetary gear on the transmission failed, two separate repairs of the transmission with the overdrive unit.