engine/trans vibration

I ended up with a bad vibration after a trans rebuild w/torque convertor. Disconnected the torque convertor slightly and fired the engine- vibration was gone. Retured converter for balancing and re-install. Then the converter threw the weight that was welded on. I no longer trade with that shop.
I thought about disconnecting the convertor but the engine cannot be cranked to start unless the converter is bolted to engine.....how would i do that?