what makes my truck pop under the front end acts like it wants to go in 4x4 when your driving?

this sounds like one for a mechanic to check.

Sounds like maybe a hub problem. I had a 4x4 F150 that did the same thing, but only when turning in 4WD. It couldn't seem to handle a tight turn without bucking in 4WD. I believe that's common with 4WD units...

sounds to me like something needs reprogrammed. lots of electronic control units need reprogrammed after a few years when the engineers discover flaws that start showing up. and yes sometimes after a few years they will find problems with the programming they reprogrammed into your vehicle and come up with something new. i would ask about it at a gm dealer.

yea i drive 2 silverado 1500 and one of them had the same problem when i would tight turns in it, but it hasnt done it in awhile so i'm not sure, might wanna take it into the shop and ask if its a major problem, seems like a lot of the 4x4 1500's have that prob