Project`67 Dart GT 340 A500

Well I had an issue while on my first long test drive, I was on the freeway and flipped the toggle and all is going well 2,000 rpm at 65 then I heard a shearing noise WTF? so I pulled off the freeway to take a look. All looked great no leaks no noise so I got back on freeway flipped toggle yep there it is again this time little louder turned off OD noise gone.....turn on again bang bang thought drive shaft fell out !! turn it off ...bang bang gone drove normal.
Back to the shop we go. Pulled transmission and found planetary part all over the place. I must have not noticed the bad part when I rebuilt it, the truck I pulled it out of had a zillion miles on it.

I had a A518 parts trans so I am swapping that OD into mine now, it will be a beafier unit and it fits right on. Lots of cleaning to do and flush everything out including the cooler and send the converter out for rebuild again. I am learning as I go here and am not a transmission expert, look those parts over a little closer this time. :O
Should be back on the road this weekend if I have time.