One problem related to grinding noise has been reported for the 1999 Ford F-350. The most recently reported issues are listed below.
We have had 3 1999 superduty's 6-speed duallys when we bought them. All started having the same problem at about 3,000 miles. Every time that you would be going down the road and you turned, the rear would make a bumping and grinding noise. You can hear it on the outside real bad. We took them to the dealership because they all started leaking rear end oil. They put the part on them, but the problem persisted. The leak had stopped on all of them, but the grinding noise still remained. We had to let one of them go back because it was so bad. The others are still doing horrible. Plus, when you put them into gear, mainly in reverse, you hear this god awful popping noise coming from the front when you start going. They all make that grinding noise in the rear end even when backing up and turning. Please help me. I have taken these trucks to the dealership so many times and yet they still all have the same problem. Thank you again.