hi, new to this forum not sure where this question belongs. I have searched but cannot find anything to describe what my truck did today. I recently bought an 06 lbz extended cab short bed 4wd and seem to be having issues with the 4wd. everything seemed to work fine when I bought the truck a month ago. today I put the truck in 4 hi while on some muddy back roads. it switched into 4wd perfectly fine and I drove about a mile like this. At the end on the road I stopped and put the trck back in 2wd. once I started driving again it still felt like it was locked in 4wd, but the push button for 2wd was lit up. about a half mile down the road, there was a huge bang and the truck went back into 2wd. shifts from 2wd to 4wd and back perfectly fine sitting in my driveway now. any ideas on what is going on would be great, thanks