Need some insight here from you guys, from the time I picked up my 99 5.9l the steering has been like trying to control chaos. On the freeway it just goes wherever it wants. Anyway spent an entire weekend rebuilding and replacing suspension components.
REPLACED
Steering gearbox,both outer tie rod ends,pitman arm, and idler arm

Inner tie rod ends appear to have life left as well as upper and lower ball joints,both sides.

Still drifts left and right, checked for play from wheel to tires and it seems responsive without to much freeplay. Is this maybe the **** joint they put in the intermediate shaft?

 

IMO, You should be able to determine any loss motion in the steering shaft joint with the ignition off and key on while one person observes and another works the steering wheel back and forth.
My '02 would get stiff to steer. Lubricating the joint freed it up. If I didn't lube it I could see the possibility of wear out there.