I tried spinning the driveshaft with the truck in park. No luck. It's locked it somewhere. When I put it in and out of 4wd I can hear something moving in there, but I can't tell where exactly. Is it best to start with the transfer case or the axle/differential? It definitely comes in and out of 4wd because I use it fairly often where I'm at. I'm assuming the front end is locked then?