for the past 3 days I've been working with my dad in construction(lots of off-road driving etc...) and on my way home today I notice that the truck vibrates real bad from the rear and it pulls to the right...I checked my tires and their fine...but I had to turn the A/C of and it got a little better(30% better)m anyone had this problem or is it the heat just causing this???

 

you sure those tires are fine? check real good inside the rims. that sounds like mud packed in a wheel somewhere. did you hit anything hard enough to warp a wheel?

 

nope these are almost brand new, but Im thinking its either the shocks or the a/c is making the motor shake.

 

check the drive shaft, obviously wouldnt make sence with the a/c part, but you never know

 

Did you happen to lose a wheel weight. Try rotation the tires front to rear and see if that changes anything.

 

I'd go with the wheel weight idea as well. Sounds very logical. Have you actually tested the pressure in each tire, or just visually checked them? I've also had a belt break in a tire and cause EXACTLY what your describing, you might just jack up both wheels on that side and check for lumps or deformaties. In the instances where I've seen it, either there was a noticeable lump in the tread, or the treaded surface of the tire was actually off-center from the rim by 1/2 " or more!