Vibration issues

Not an automatic guy but it sound's like Duane has some good advice.

In the OP picture it appears the housing is drilled for a balancer weight. Since the vibration was an after effect to the gear change, I'm sure this would not be his issue. I'll just post net found pictures for reference what it looks like……...
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I am not saying his vibration problem is the trans. I am saying that when his driveshaft fell out of the car at 60 mph that could have created a separate problem. I've seen plenty of torqueflites blow up at the track because a previous driveline failure damaged the roller clutch and it was not checked. Later the trans is run again and kaboom.