I have always had a small vibration in my truck but now it is getting worse. A few weeks ago i got it in the air and noticed the idle arm bushing were gone. I replaced them and the vibration got worse so i checked the steering and i had play in the pitman arm and the passenger tie rod end. I have replaced the pitman arm and drivers and passenger tie rod end and the vibration seems better. I have new tires that were balanced a few weeks ago and I still have a vibration that i cant find. It doesn't get worse when stopping and generally gets worse over 45mph but not always. The vibration is always present but gets better and worse sporadically. Any Ideas?