Popping in 4-wheel drive

[T-Bagg]

So driving around in two-wheel drive there is no noise. Only a slight clink while I'm driving around slow sometimes. But when I put it into 4 and give it gas I get a loud popping noise. I just replaced the CV shafts so I know it ain't that.
Help would be appreciated. Any trouble shooting tips. I have very basic knowledge of car and truck mechanics, any thing past bolt on and I ask for help.

 

[tim@sp]

did you check the u-joints for the front shaft?

 

[mygreen98]

i agree, check all ujoints.