vibration when accelerating

Like the title says, I have a vibration when in the throttle. It goes away when coasting or braking, and the speed when I apply the throttle or the amount of throttle doesn't seem to change it (other than it is faster at higher speeds). What would cause it? I have the 6spd so it isnt trying to shift gears.

Some of my online research points to drive axles....?

 

u-joint... had same thing happened to my previous 05

 

Would this be worse with weight in the bed?

 

Possibly, the driveline angles will change a bit.

Change it out before the driveshaft kisses the asphalt

 

I would imagine just more added stress to the driveshaft.... When mine started doing what yours did, I had my mechanic look at it and said all mine were bad.

 

did you lift your truck ?