4 Wheel Drive/SUVs: Steering Stiffness, jeep grand cherokee, steering linkage

Question
I have a 1998 Jeep Grand Cherokee that I lifted 2.5" and put 32" BFG's on.  Lately I have had stiffness in the steering when I drive for extended periods of time.  And once it acutally stalled out. Not sure what the problem is but I have had it for almost a year now and this is the first time this all-time 4x4 has done this.  Basically I am trying to narrow down the issues that might cause this.  Any help would be greatly appreciated.

Answer
Adam,
  Without looking at the Jeep, I would guess that you have a power steering pump going out.  Many times, you can tell if this is the problem, as the pump may start to make loud growling sounds when you try to steer.  To a lesser degree another possibility, is the steering box itself, or a failing component in the steering linkage.
  A reputable front end shop should be able to check this out for you.

     Carl