A few years back I split my 1370 and replaced all the clutches and updates to the new style pistons also. After a few years of tillage work she let me down after about a total of less then 50 hrs. I was disking a field and decided to unhook the disk, and drive about 2.5 miles back to the farm to hook up a different heavier cutting disk. Drove down the road with no issues. Backed up and hooked up the disk and pulled it back to my shop to air up the tires. Now, as I pulled up to the front doors I turned to the left and pushed in the clutch to go from 3rd range to 2nd range reverse. That's when a horrible grinding kinda sound came from the rear end area. I hurried up and put it in neutral and let the clutch out. The noise stopped and the tractor just idled normal. When the C4 clutch is engaged is when the noise happens. So I figured something happened with the planetary gears. Its in my shop now getting ready to be split. Any ideas what happened???? Thanks in advanced!