V30 TH400 making noise... bad converter?

[5Tractorguy]

If this is in the wrong section please move. Figured since it was in a square body...

Just put a freshly rebuilt TH400 back in my 1-ton with the same converter (converter was new 2,XXX miles ago).

Doing the SAME thing as the transmission I replaced it with. Get it up to speed and back off to cruse, it's like the transmission falls out of gear and "no one's home" when you push the pedal, engine winds up. Only way to get it to catch again is to punch the pedal quick and it grabs.

Coming to a stop I can hear a rattling (watch video below, starts at 5sec). It was louder before hand.
https://www.youtube.com/watch?v=wvp8ayRvs2k

Sound like a junk converter? Shutters a bit when I back up the drive and first take off.

Any help/thoughts are appreciated. After having the trans out of this thing 3 times I'm at wits end...