One problem related to power train driveline has been reported for the 1999 Ford F-350. The most recently reported issues are listed below.
Driving my 1999 f350 Ford crew cab long box. Veh is a 7. 3 diesel with a 6zf 6spd transmission. Traveling 75mph the vehicle develops a mild vibration. I push in the clutch to pull out of traffic, the rear drive line flange bolts sheer off at the transfer case, the drive line knocks a hole in the floor board of the vehicle caves in the catalytic converter tears out the carrier bearing and separates the two piece drive shaft. The rear section of the drive shaft hits the right rear wheel sending the rear of the truck airborne and breaking the drive line off at the rear axle. Further inspection I find the transfer case has been torn from the transmission extension housing destroying the transmission housing. This truck has 124000 miles on it has never had work on the drive train. And inspection of the drive train less than a year ago showed no signs of excess wear.