Re: 4x4 not working question
When your jeep has the full time 4x4, then it has the NV 247 T-case. This T-case has a progressive coupler, which will transfer the torque partly to the front wheels when a speed difference between the front propeller shaft and rear propeller shaft exists. So when 4 Lo works ok, but 4 automatic not, most probably the progressive coupler is inoperative. Firstly check the fluid level and the fluid itself for eventually metal particles or other contamination.
When 4x4 doesn´t work in automatic nor 4 Lo, then there is something else wrong inside the T-case. It could be that the chain inside the T-case is broken or stretched too much that it left the sprocket. An other possibility is that a previous owner just removed the front propeller shaft due to problems with the joints, that is easy to see if its there or not.
JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
Monroe Reflex shocks /
Pirelli Scorpion ATR 245/65/17/
Transgo reprogramming shiftkit.