Got a 2015 2500 Cummins and I'm pretty sure my 68RFE is about to go.

The truck has 75k on it, deleted with race me and DRD tune, running 30hp right now.

I don't go crazy with power and only step on the skinny pedal once in a while.

Trans is stock apart from Revmax valve body pushing 225 psi main line pressure.

Here's the problem, when torque converter locks up, especially in 4th-6th there's a terrible sound like something is rattling/knocking around the bell housing.

When I'm just rolling at light throttle (5-20%) the sound does not stop unless I let off throttle.

If I give it more throttle the rattle gets a bit louder but then goes away when the boost kicks in.

I can feel the rattling/knocking through my feet and can hear it when the windows are up.

The shifts between most gears are pretty rough even after the valve body swap but the truck feels great in terms of performance.

Does anyone know whats going on?

Loose torque converter bolts? Flexplate? Clutchs?

Any ideas?

Thank you.