Justhorsenround is correct. This post needs to be in the driveline forum or general truck talk.
Without seeing photos....you got pics? I would guess that the bushings around the king pins are worn out or gone, or you've got a spindle problem as Fred has noted. Pics would REALLY help with diagnosis. Both king pins need to be replaced as a set, right and left. Suspension parts as a rule should be replaced in sets whether it is front or rear. Look at this as a job per axle.
Tim
Last edited by fixit1958; 02/19/2015 10:44 PM.