Its comes at diffrent speeds, it is kind of like a tire out of balance or like i am running over reflectors in the road that are close together. I don't think it is a tire, my rear drive shaft seems to be fine.
There is some play in the front drive shaft but it doesn't spin unless in 4wd right? could this be a wheel bearing or something. I think it's coming from the the front driverside. what can i do to find out? or is this an engine/injector issure and i just think its drivetrain.
help.

Wheel bearing is my guess, I have the same vib and jacked my truck up and sure enough there is play in the bearing. I only have 39,500 miles on the truck:mad:

I have a similar issue, but mine doesn't seem to be a wheel bearing. I think I've checked everything it would make sense for it to be...

i'll jack it up and see if there is play in the front wheels

I can take the front driver side tire and push the top of it, while jacked up ,and it moves back and forth. I guess that means wheel bearing. i have just over 100,000 miles.
Can I fix this, or do i need special tools like a press, etc?

You can do it yourself just did mine on Sat. The thing you will probably have to round up is a 1/2" torque wrench that goes to 250ftlb, got mine at Auto zone loner. hear is a link with directions http://www.dieselplace.com/forum/showthread.php?t=71798&highlight=wheel+bearing the bearing was 232.00 at Advance auto parts.

does anyone know if a bad wheel bearing would cause intermittent pulling issues? I'm pulling to the left with similar vibrations/noise.

does anyone know if a bad wheel bearing would cause intermittent pulling issues? I'm pulling to the left with similar vibrations/noise.

Yes it could, due to the bad bearing causing friction on that side.