2010 HHR, just lowered and now a clunking sound.
 

Hello names Jeff, I lowered my 2010 HHR with Goldline Springs, 1.75f/2.25r, yesterday. On top of the springs, I purchased struts, shocks and sway links. I understand lowering changes geometry for most everything. However, a knocking noise has started in the front end, on rough roads and when steering but only as the wheels approach the straight position. Can anyone enlighten me on this and/or direct me to a similar thread? I would greatly appreciate it.

Additionally, I have not gotten an alignment yet, which I also purchased the camber bolts, could this possibly remedy the issue? Thanks again.

In general follow the link in my sig.

In particular, sway bar links may be worn out or the wrong length. 9.86" is the correct length for non lowered, don't know about lowered. If you got 12" links, that's a problem.
Yes the camber NEEDS to be adjusted after lowering.
The LCA bushings need to be inspected closely.

Double check the torque on your fasteners, have a look at your lower control arm rear bushings, and the sway bar bushings.
But double check the length on your sway bay end links and the torque on the nuts!
Let us know!