In my case, I had downward sagging doors. The problem is that the door and the jam is sheetmetal. The hinge is 1/4" thick, so if you try adjusting with a 2x4 in the jam the only thing that happens is you put a 2x4 shape dent in the jam or the door. Instead, I took hinge apart put the part of the hinge that goes into the pillar and adjusted it in the vise (with a BFH). The direction of the adjustment is as shown in the picture below. That lifted the bottom rear (of the door) up and tilted the top front (of the door) foward. And no damage to the door or pillar.
[img]http://img.villagephotos.com/p/2003-9/378428/Truck1.JPG[/img]