One problem related to driveshaft has been reported for the 2004 Ford Explorer. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford Explorer based on all problems reported for the 2004 Explorer.
Delay in transmission engaging in either reverse or forward gear is highly dangerous because auto suddenly slams into gear and lurches forward. This has also occurred at highway speeds when the gear suddenly engages and causes a severe lurch forward with a bang so severe I thought I had hit something. Also, there is a chatter when accelerating during a turn and vibration of the driveshaft at varying speeds. I was told by the service dept. When I complained after purchasing the car that this delay was normal. On the second visit, they replaced the differential which caused a vibration and whine in the drive train. I returned it and the differential again was replaced and the drive shaft balanced with no improvement. I have been waiting for parts for quite sometime. The fluid additive is not available nor has the solenoid been replaced, but I understand this does not work either.