Steering prob could be, bad tie rods, bad ball studs (ball joints), or steering box out of adjustment. You need to get under the front of your truck and have someone turn the wheel back and forth. Look for the parts that move where they connect to the parts that don't. There will be your problem. Changing axle ujoint isn't hard, just a pita. You do not have to remove ball joint to do this. Remove locking hub, brake caliper, wheel bearing and rotor. There will be (can't remember which) 5 or 6 bolts that hold on spindle and brake backing plate. Remove the nuts, remove spindle, and pull axle out. Be careful putting axle back in, you can damage the seal if you force it. Now is a good time to change axle bearing and wheel seal too, since you have it apart. Just remember how the hub nuts came apart. Do you mean full time 4x4? No lockouts on hubs? If so remove dust cap opn the end of your axle no the lock out . You will need a special socket to remove the wheel bearing nuts, about $10 for it. hope this helps, Bob