I just finished replacing the steering sector on my work truck, with cannabalized parts from another. The pitman arms had to be changed (the replacement was from a 2WD, going into a 4X4..) The pitman arm resisted all efforts using a puller and smacking the puller shaft with a 3# hammer. A usefull trick is to use the hot wrench to heat to pitman arm (On the outside, away from the seals.) All it takes is a little warmth to swell the pitman arm enough for a good tap with the hammer on the end of the puller to free it.... This might not be what you want to do if the sector is still in the truck and covered with grease and oil, etc....