# Interesting knocking sound from rear when hiring bumps



## IndianCruzer (Aug 19, 2016)

I am guessing that you can start at the main bush in the rear. Check out the diagram. The blue bush.


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## winks79 (Dec 20, 2013)

Since it is and LTZ, it has rear disc brakes. I would start there. This is where I found my rattles coming from. Both calipers do the same thing on mine. Started around 17k miles and as the pads have worn, it has gotten worse. When going over these bumpy roads, I can apply the brakes and the rattling will stop, as soon as I release the brakes it begins again. Crawled under car and found the the pads and parts of the caliper are what is making the noise. I can wiggle the caliper and make the noise while under car. Will probably go away when I have to replace the pads again, but as they wear, the play will come back in and cause the rattling again, I'm sure. Others have had shocks replaced, suspension parts loosened and re-tightened, but this has been my issue. Little annoying, but does not bother me near as much knowing what it is now. I did make sure everything was tight, and it was. Non 4 wheel disc brake cars may have some other issue, but as stated, I would check your rear calipers and see if yours has the same problem as mine.


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