Howdy! I have a 1993 Ranger xtl 4x4 5sp 4.0

Anyhow I have a front end shake that I can't figure out. First of all, it doesn't do it all the time. About 50% of the time I'd say. The truck also pulls to one side. Neither wheel has any play when you jack it up and shake it. The bearing and ball joints are new (A year ago) and I've already checked to see if the bearings are loose. The shake seems to be coming from the passanger side, and when I spin the rotor it is easy and then hard, easy then hard…. Any idea as what I should check next? Thanks!