You can find out for yourself, have someone move the steering wheel back and forth (works better with engine off), you look under the front and see where the slack is. Everything should move together smoothly, if not the place that has the slack is bad.
When mine was loose, the problem was the idler arm.
You can get more life from your steering components if you grease them regularly. There are 11 grease fittings on the front of these trucks. (beat you to it BlazerLT
)
2 upper ball joints
2 lower ball joints
2 outer tie rod ends
2 inner tie rod ends
2 on the idler arm
1 on the pitman
Just grease them until the rubber boot is firm to the touch. I use two grease guns, one with a hose and straight end, and one with a 90 degree fitting for the tight places.