01 Transfer Case Broken???

I have a 2001 Silverado 2500, 6.0, NP8. the service 4WD light started coming on and then the 4X4 quit as usual. I could hear the transfer case shifting but when I would try to go back to 2WD, it seemed if the tcase would stick in between gears..as if in neutral. I figured the transfer case motor was going bad and wasnt shifting it properly. I replaced it with a new unit and im getting the same results. I was checking if the 4WD was working down a dirt road and it wasnt. I put it back in 2WD and started driving home and got about 1/2 mile down the road and the motor revved up and wouldnt go anywhere. I messed around with the 4WD buttons and then it locked back in gear and started going again.

I put it back in my shop to do a bit more checking on other things. I jacked up the drivers tire and it spins freely. Lock it in 4WD and it locks in as it should. Just to be sure I pulled the front axle actuator out and verified its operation by having a helper shift it into 4WD and watching it work. I also made sure that the parts inside the actuator hole moved freely and they locked in just fine. When its locked in 4WD I can turn the front wheel with HAND FORCE. Its stiff to turn but still I dont think this should be possible if the transfer case was in 4WD.

What I am suspecting is that something came apart or broke in the transfer case and isnt locking things together. It does all the above even when in 4LO which definately tells me that it is shifting.

Any ideas on what could be happening???

I have a 2001 Silverado 2500, 6.0, NP8. the service 4WD light started coming on and then the 4X4 quit as usual. I could hear the transfer case shifting but when I would try to go back to 2WD, it seemed if the tcase would stick in between gears..as if in neutral. I figured the transfer case motor was going bad and wasnt shifting it properly. I replaced it with a new unit and im getting the same results. I was checking if the 4WD was working down a dirt road and it wasnt. I put it back in 2WD and started driving home and got about 1/2 mile down the road and the motor revved up and wouldnt go anywhere. I messed around with the 4WD buttons and then it locked back in gear and started going again.

I put it back in my shop to do a bit more checking on other things. I jacked up the drivers tire and it spins freely. Lock it in 4WD and it locks in as it should. Just to be sure I pulled the front axle actuator out and verified its operation by having a helper shift it into 4WD and watching it work. I also made sure that the parts inside the actuator hole moved freely and they locked in just fine. When its locked in 4WD I can turn the front wheel with HAND FORCE. Its stiff to turn but still I dont think this should be possible if the transfer case was in 4WD.

What I am suspecting is that something came apart or broke in the transfer case and isnt locking things together. It does all the above even when in 4LO which definately tells me that it is shifting.

Any ideas on what could be happening???
get dtc codes will look up failure could be many things

Sadly I dont really have access to that equipment

Autozone will scan your truck for free.

Sorry for the delay in response. Work has kept me too busy to deal with a vehicle problem

I got the computer scanned and it is showing a code C0324 -C0324 T-Case Lock Circuit High.

Anyone know what this means and how I fix it??

Sorry for the delay in response. Work has kept me too busy to deal with a vehicle problem

I got the computer scanned and it is showing a code C0324 -C0324 T-Case Lock Circuit High.

Anyone know what this means and how I fix it??

this code means that the encoder motor or wires going to it are drawing excessive current! motor/wires? tan wire that goes from control module to encoder motor possible short or bad motor........