Hello, I'm Danny.
Your fan blades are bolted to the fan clutch assembly.Here is a tutorial for you to see about removal and replacement.After removing you will have access to the bolts to tighten.Here is a tutorial showing what is involved:
I've attached picture instructions below for your Trailblazer.Hope this helps and thanks for using 2CarPros.
Images (Click to enlarge)
Saturday, May 9th, 2020 AT 6:42 PM