I might need a transmission. Started out as a grinding noise when I was on the highway. Came out of nowhere. Was doing 70 and hear the noise which I think was coming from the front right tire area. I started to lose power, couldn't keep speed, so I pulled over. Looked everywhere, no fluids, everything looked okay from the surface. I started it back up and the grinding was there, but I drove home at 30mph, no issues, everything performed, trans shifted etc... I take to my mechanic, he pulls the wheels, transfer case covers, nothing so far. All clean. Now though, when you start the truck, and put it in gear, I hear a grinding and it doesn't move. Just a grinding. I tried center dif lock, nothing.