Put a circle d 278mm converter in a 6l80e paired with a 5.3 lmg gen iv. Spacing was good on the converter, fluid level in trans is good, it shifts though the gears fine and doesn’t make any noise under light (under 30%) throttle, doesn’t make any noise while just sitting still in any of the gears. But giving it above 30% throttle from a stand still or while rolling causes a grinding noise from the converter area. I’m thinking it’s a tuning/software problem based on some research here but any help would be great

 

Is the engine torquing over and hitting the exhaust, a shield or frame?

 

Are the dust covers loose? One of mine would get in to the ring gear under power, added a flat washer and tightened the bolt up got rid of it..

 

Forgive me, I am not very familiar with Circle-D Products for the 6L Family...

Is this at least a Billet-Half Torque-Converter?

Stock Type TCs can half all kinds of Odd and Fun issues.

 

Cracked flex plate?

 

I would be inclined to think it is something related to exhaust, heat shield etc. It doesn't sound lockup related, but you can hook up to HP Tuners or your software of choice to verify. Just see if lockup is commanded on when you hear the issue. Bearing noises typically manifest as more of a whine, so I don't think that's what's happening here. If you can't find anything on your end, feel free to give us a call at the shop and we can continue trouble shooting.

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