What would cause a sound as if something is loose in the torque converter. on 2002 GMC Sierra 1500 HD

Mostly happens under acceleration. I had the torque converter replaced but the noise is still there.

2 answers
Could be several things, need to have someone use a stethoscope to isolate the problem. Sorry that the Converter was not it, did the shop misdiagnose this? If so, why don't they stand behind their mistake?
I WOULD TAKE A LOOK AT THE FLY WHEEL IT MAY BE CRACKED.