So thats what its called! I had a government work truck that had this problem from the day it was new. A 2006 Dodge 2500 quad cab 4x4. I would turn it in and try to explain to the dealer what was happening and they would check the frontend for bent tierods and such but were never able to fix it. I hated that damn truck! It would usually happen at about 60-70 mph and hitting the smallest bump in the road would set it off. Happened once while passing a semi on the interstate and I thought I was gonna see Jesus.
Better days now, It's been replaced with a F250.