First off i would like to start off with a little background about the truck. It is a 2006 Silverado 1500 Crew Cab with the 5.3 liter motor and a NP246 Transfer Case. The truck has around 130k and is very mechanically sound, except for the 4wd Issue. The Transfer case was fully rebuilt not long ago and a new selector switch and encoder ring was also installed along with a new front axle actuator.. Heres the issues. The Truck does not have normal 4hi or even 4lo. But when auto 4wd is selected it will spin all 4 tires fine when needed. When on jacks and with 4hi or low engaged you can hear all the actuators firing but but there is little to no power to the front wheels. As of just a few nights ago the selector switch on the dash has been going crazy indicating that it is shifting into 4hi, auto 4 and back into 2hi but you cannot hear the actuators actual firing. On my way home from work the neutral light came on and stayed on and would not allow me to select any other options until after i got home and parked it then put the truck into neutral and bam everything started sounding like it was shifting again. But still no actual 4wd just the auto function.(After all these events i still dont have any codes or service 4wd errors on my dash.) I was told it could be a tccm error, a transfer case module issue or even the actual encoder motor not shifting correctly. Im on a budget as i am going to college and would like this issue resolved somewhat timely. Any opinions would be appreciated on what is going on.