Alright, a couple months ago I had a Auto hub fail on me, and so I replaced it with another unit. When I replaced it everything was fine for a few weeks. Then the whole axle assembly which interlocks with the auto hub failed. It was pretty chewed up from the first hub failing. So I get a junk yard unit which looked really good. Replaced everything and was doing great. Then out of nowhere one day anytime I put the truck in 4WD I got a few large bangs, and I took it out for fear of damaging something even more. I switched the hubs thinking it was possible that they are side specific and that actually worked. Then yeseterday we got hit with a snow storm, and I was driving myself out of a 2 foot deep snow bank at the end of the driveway caused by a plow and I got through with no problems. I had it in 4WD Low. I went to take it out of low and no luck. It won't disengage out of low nor out of 4WD at all. Because its in low, I get no downshifts and I can't drive anywhere without redlining the damn thing. I just need to know what to check and how to resolve this problem ASAP. I hope I've given enough info. Thanks in advance for any help.

 

Seeing as you got it into 4x4 low, I'm assuming you knew to put it into neutral and foot on the brake to take it out of 4x4 low? Try resetting the control module in the rear quarter panel where the jack is stored. Also, try lightly tapping on the shift motor on the transfer case.

 

What happens when you hit the buttons? This will help diagnos.