I can only drive in 4 wheel drive?

Lukkly you got a truck cuz if you had a motercycle ya woodent be able to drive it cuz they got 2 wheels.

We are having same problem with 2005 z71 , did you end up fixing it?

Problem Solved: My 99 dodge ram 2500 is doing the same thing. When its in 2wd and I put it in drive or reverse, the transfer case whines and doesn't go into any gears. But when I put it in 4wd, it goes into any gear fine with no noises but drives with only the front tires... So my guess is the gear/sprocket/chain that transfers power to the rear end needs to be replaced. You can see a bad chain if you take off the 4-5 pinion yoke housing bolts on the drive shaft side of the transfer case and also undo the closest u-joint and pull the drive shaft and housing back enough to look inside with a flashlight which you will see the gear and chain. Check to see shavings stuck to the gears when you drain the fluid. If so, that will indicate that you need a new chain/gear/sprocket set (which is my issue with not driving in 2wd and only the front wheels driving when in 4x4.) Meaning that only the rear end isn't functioning.