One problem related to steering knuckle spindle has been reported for the 1999 Chevrolet C/k 3500. The most recently reported issues are listed below.
I had no warning, no vibration or slop in my steering. Luckily my son had just came in with the truck. I went out and started backing up and all of a sudden the front left (ds) wheel dropped to the ground. I inspected it and found that it looks like the spindle had broken just before where the bottom ball joint is. Approx 1" from the a frame. Wonder what would have happened if someone had been driving it??????? I didnt see any signs of damage or where it was hit. It just looks like there was a failure in the spindle?????.