It's most noticable during low speed. It seems to come from the center of the truck towards the back of the vehicle, not from the engine. It may be the u-joint, if so how much would that cost to repair?
It only does it when accelerating, and the squeel gets faster as you go faster.
I have a 1996 Ford Taurus, My belt had broke once and I had to replace the Idler pulley and get a new belt. We I just put the new belt on and ever since then I hear a squeeling / screeching sound where the belt is. Also when ever I run the heat on high is when it makes that sound the most, also...