Originally Posted by The black pearl

Hey i believe that you can tell if steering box is worn out by amount of play in steering wheel by amount of correction to wheel to maintain a straight line. You could probably reach down in to engine bay and grab steering shaft and check play. If you are actively correcting steering when driving you got something wonky. You said it really binds in 4wd then most likely the front diff the pinion is not allowing the proper gear meshing and the limited slip is not functioning. Or quite posibly it is transfer case not being disengaged by a solenoid/actuator being somewhat engaged. The only way to see if transfercase is in is on a lift or with a mirror positioned underneith (or an annoying apprentice )to see if front shaft turns when you drive slow. If you lift up and turn tires if shaft turns(2wd) it is stuck in diff. If not it is stuck in transfer case.also look on youtube for death wobble videos taken inside cab and compare if video is same as what you experienced. Hope this helps out .