Grinding noise when in gear and doesn’t move

I have a 2008 Tundra limited with the 5.7. I recently replaced the wheel bearings on the rear axle because the truck was throwing ABS codes and that’s what Toyota diagnosed the problem to be. Since I didn’t want to pay the ridiculous amount to get it fixed, I did the job myself. After putting the rear axle back together, I wanted to test the truck out to see if it worked. As soon as I shifted the truck into either reverse or drive, it makes a very loud grinding noise. When I try to give it gas, the truck doesn’t move. I then shifted the transfer case into High 4 to see if it would move and it did move once it’s in gear. Since it moved in 4WD, I figure the problem is not with the transfer case or the transmission, but with the rear differential itself. Could the axle shafts not be in all the way? Or is something possibly wrong with the differential itself? Also when I jacked the truck back up to spin the rear wheels by hand, I noticed that there is a loud clicking sound whenever I spun the wheels.