Hey guys, I posted a month or so ago about our 4320 that locked up suddenly while driving down the road in 8th gear. Well we dug into it today and it was exactly what y'all had described. The differential cross shaft came out about 2", hit the trans pump and destroyed it and then hit the pinion shaft severely damaging it. The ring gear also has some damage. When it hit the pinion shaft, it sheared the portion of the shaft completely off. So, looks like we have a lot of work to do. This tractor did a lot of plowing with a 5 - 18" plow back in the day with the previous owner so that might explain it as Tim S described. I have attached a few pictures of the damage. Thanks for the help.