Rear drivers side thump
 

07 Monte SS original owner 107,000 miles.
Last spring a small thump,clunk,tap noise developed in the drivers rear. With 90+ miles I decided to do rear struts. Replaced the strut and mounts with OEM.
Noise still present, Then I replaced bushings for rear sway bar along with links. Then Both rear trailing arms, both sets of (control arms?) going side to side. and finally both wheel bearings. Yes while I was under there new rotors and brakes. THERE is nothing left to change. Still the noise.
I dropped the back seat while the wife drove the car around and I could feel the bumping on the strut top.
I don't see any rust on the metal. Tried retightening the strut top nut. I found a TBS to cut the rubber tabs from the coil spring. NO LUCK.
I wonder if the new strut could be bad? I recall it only took like 8-10lbs to push down or extract it.
Tomorrow I plan to tear it all apart hope to find something.

Wow, thats frustrating, Doesn't sound like you missed anything. The GM braces tighten things up a bit, might help some and they can usually be found in a junkyard or are inexpensive new as well.Need the custom brackets for these cars too. Look around some, its a good investment anyway as they for sure work. Post back your findings, good luck!

https://montecarloforum.com/forum/fw...r-brace-27280/

Did you ever figured out what the problem was? I been having a similar issue on the right side going over small bumps. I’ll be changing out my springs/struts, mounts soon. Do you have lock collars on your sway bar (addco). Those collars hits the frame when the vehicle is compress, you must grind the down.

Do you guys have the inverted Bilsteins?