My truck has a pretty big turning radius. I can't seem to even make a U-turn in a 2 lane road with a middle lane. Is this just the way it is, or could something be catching/hanging it all up?

 

I can flip a u-ey in a two-lane residential road- about 32' across- with both my 88 4wd 4Runner and my 91 2wd x-cab. The 91 actually turns sharper than the 'runner but it has a slightly modified front end (lift kit) that has changed the turn radius. If you're having troubles doing so, it's possible that an alignment was performed with the steering box not at center.
To check, turn your steering wheel full left. Then turn it full right and count the number of turns, including partial turns. Then divide that count by 2 and turn your wheel back left that much. If your steering wheel is not very close to center (say within 1/8 turn) and your wheels are not pointing straight ahead, you need an alignment.

 

Hmm... I dunno. My 89 4runner could pop a u-ey in less than 2 lane road with median.

Though this 84 of mine damn near needs 4 lanes. Was thinin about this myself earlier today.