GM Repair Problems? Ask GM Repair Expert Now.
Your wave plate broke for sure if there is metal in the fluid. I used to do a lot of these. What happens is the wave plate from factory is too thin and over time cracks due to heat. That plate (which acts like a spring for the clutches) still functions for a while when its cracked but once it falls apart into multiple pieces, its over. The transmission has to be taken apart and and replace whatever is damaged. Usually that whole 3-5-reverse housing and associated clutches. The TCM can have faults. They have pressure sensors that fail and will set a code. I used to always replace the TCM anytime i had the transmission for the wave plate issue.
What are your exact symptoms. The waveplate breaking will cause you to have delayed reverse application and no 3rd gear or 5th gear. The TCM can give a slew of issues from a harsh shift or no shift at all.