TCMagnum

Well I think the old man's truck is fixed...
I had a gut feeling before  tearing into the trans, something less invasive should be attempted first,  after some more reading about the 47re online, and noting some "weird" issues caused by the output speed sensor, we removed the OSS and found this. ,(see picture)
Installed a new speed sensor and he took it for a test drive, got it up to operating temperature and drove 30 miles round trip with NO issues,  and most important,no  random kicking out of overdrive. Which before you couldn't go 5 miles without it happening.