I did tighten the pulley to the bearing correctly.

I went back through my orders and EPC to confirm the part number and I may have found a source of error. I haven't confirmed this yet, but I may have installed the wrong fan bearing bracket

M104.980 calls for part 104 200 05 28. I have a 95 E320 with the M104.992 that needed a new fan bearing bracket as well and I ordered it's part 104 200 13 28. I ordered both online at different times and labeled their boxes which one goes to which car, but there is a possibility for a mismatch either on my part installing the wrong one or the retailer sending me the wrong part.

I hope there's a part number stamped somewhere on the metal I can reference to see which part I installed for which car.