AOD issue
Reply #2 –
A bad valvebody seperator plate gasket or warped valvebody. My old car got to the point where it would occasionally drop out of gear and violently slam back in at very inconvenient times. Just loosening all the valvebody bolts, tapping the valvebody loose, then retorquing the bolts starting from the center and working your way out. This was also an issue on C4's.
I've seen plenty of units overhauled because of such simple problems.
Good luck,
Don