2007 Yukon xl 4x4 issue...frustrating!

[Cmgallus]

I have a 2007 Yukon xl. Sometimes when in auto 4x4 it will show 4 wheel drive service and go to 4x4 instead of auto. It also makes a howling noise. To get back into 2 wheel drive I have to shut the vehicle off, remove key, and open the door for the vehicle to cycle down. Then when I restart it will be in 2wheel drive. I thought it was the actuator on the transfer case so I replaced with a rebuilt one I bought. I had to take it apart and set the timing but not sure if I could be off. I still have the same issue. Could I have an electrical issue being that it does work sometimes?

 

[Cmgallus]

Has anyone had this issue?

 

[MCAT069]

Check your grounds and the plug on the transfer case shift motor. I had this issue on my 04. The ground by the driver's door was loose and the plug on the shift motor got water in it.

 

[Cmgallus]

Still having this same issue but now it hums all the time in 4wheel drive. Auto 4x4 goes to 4hi. I also noticed that only the back wheels spin and the front does nothing. Could this be the encoder ring is off or something else.

 

[Cmgallus]

I replaced the encoder ring on the transfer case. No more hum but the 4x4 still don’t work. I took back off and I can’t turn the gear on the transfer case. Is that normal or should I be able to turn it?