Clunky rear suspension

I recently replaced struts and shocks with Koni Aktiv kit and replaced the coil springs with Sufflex lifting springs, which gave me aaprox. 2" lift, which is very helpful for my applications. I also replaces front and rear strut and shock upper mounts. The car is rock solid at highway speeds and feels surprisingly sporty when going in corners. But it has horrible clunk coming from rear end when driving on dirt roads or going over bumps. The clunk was pre-existing, and it was a what motivated me to replace the suspension. While front end feels smooth, the clunk from rear feels even worse than before. I looked under the car and everything seems in place. I am wondering what the culprit can be.

I would check bushings on the rear lower control arms and the rear trailing arms (I think that’s what they’re called). If the bushing is compressed on one side or if the bolt is not sitting dead center, that might be enough to cause clunking on speed bumps and such. Bushings should appear to be solid- they shouldn’t look like padding that compresses. Signs of dry rot or cracked bushings can also allow enough wiggle room to create clunks
Congrats on the new suspension. Let us know how the Koni Actives are. I’m wondering if there’s any actual difference between those and the FSDs that they replaced.

For me, it was the rear sway bar end links that did the trick.

D-Cup said:

I would check bushings on the rear lower control arms and the rear trailing arms (I think that’s what they’re called). If the bushing is compressed on one side or if the bolt is not sitting dead center, that might be enough to cause clunking on speed bumps and such. Bushings should appear to be solid- they shouldn’t look like padding that compresses. Signs of dry rot or cracked bushings can also allow enough wiggle room to create clunks
Congrats on the new suspension. Let us know how the Koni Actives are. I’m wondering if there’s any actual difference between those and the FSDs that they replaced.

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Konis are awesome. To be honest, I just wanted to replace the stock springs with stiffer ones to increase ground clearance, and I was recommended to uses those Konis togeher with stiff springs. I think they are worth every penny, handling and ride quality are day and night compared to stock suspension.

I had the same problem, sounded awful. It started when I replaced the rear springs and shocks and was coming from the left side. Replacing the left sway bar end link fixed it.
Seems as if the suspension design amplifies small noises, I could only hear a slight click out of the car but it was very clear inside.