S40 suspension clunk/knock

sbowz · Post by **sbowz** » 02 Nov 2009, 18:39

I have a 2004 S40 (US) with 122,000 miles on it and there is a clunk/knock type noise in the right front floorboard area when driving over bumps. I replaced both front struts, top mounts and top mount bearings (all definitely worn out). I also replaced the left front control arm due to a worn ball joint. The car now drives and handles like new but the clunk is still there. I spent quite some time inspecting all the front suspension components and nothing is showing any signs of wear. The "parts till it starts" mentality does not sit well with me at all. Any thoughts on what is causing this clunk noise?

keithatcpt · Post by **keithatcpt** » 02 Nov 2009, 19:51

You might have bad stabilizer/sway bar bushings. I had a minivan that had a very expensive sounding clunk from under the floorboards. Turned out that the sway bar bushings were completely shot, and the metal bar against the metal frame member was making a horrible noise on every bump and dip in the road.

The bushings are basically held in place by two big wire loom clips. All the bushings are are rubber pads around the sway bar. The replacement procedure looks to be a bit more complicated on the S40 than on my old van, but it's worth a look.

- Keith

jtz54 · Post by **jtz54** » 14 Dec 2009, 17:26

I've had both of the sway bar bushings break. Each time a loud clunk can be heard. If only one side breaks as it usually does, the clunk will disappear when going around a curve. When my left side broke it didn't cluck when going around right corners/curves. I believe there was a recall on these since they are made of aluminum. An early warning that the bushings are going is groaning over bumps.