You have the 2wd pitman arm, it doesn't go bad... Yes, it's pressed on to the steering box... What needs to be changed is the link from the pittman arm to the center link (if that is the problem) and it's about 20 bux...
The 4x4 pittman arm is only 30 bux and has the balljoint built into it...
here is a pic of a 2wd set up....
