Rear Clunking Sound. Help!
 

Around 2 weeks ago, I decided to swap out my Eibach Sportline lowering springs for some RCE Yellows. I believe I installed everything right. Made sure top hat nuts were good and tight, made sure everything was the right torque spec. However, I am still getting this popping sound from the rear. It seems I am getting this popping sound when I approach a driveway on de-acceleration under 20 mph. I checked the torque of the lower control arms, checked the rear end links, greased the springs with white lithium grease, and the sound still persists.

I got under the car today and saw that the aftermarket lower control arms were off a little on the passenger rear, which is where the noise is coming from. Does anyone think this could be the culprit?

Here is both of the pictures of both sides where the LCA attach to the car.
First pic is the Driver Rear (no noise)
Second pic is the Passenger Rear (noise)

hard to say. May be the ball joints. I'm replacing mine at the advice of my mechanic. There are some nice aftermarket ones out there. My clunk happens on track at 1G lateral or more

Bubba says to give it a shot of kerosene and see if the clunking stops.

:iono:

What brand are those control arms and how long have you had them?

No idea what brand they are. Bought the car with them, and I haven't been able to figure out who they are from. No label or engraving or anything that can identify them.

Hmm to me it looks like there are cracking/destroyed parts of the spherical bearing dust boots. That combined with these being from an unknown brand I’d personally replace them.

If you disconnect the other 3 control arm bolts, you should be able to shake it around and replicate the noise.

Will do that and report back.

What LCA brand would recommend?

I have the whiteline rear arms which are just oem arms painted silver, slotted for camber adjustment at the hub, and a whiteline poly bushing where it mounts to the car. Highly recommend them for someone not looking to break the bank.

https://www.ebay.com/itm/Whiteline-R...-127632-2357-0

I am not sure on all the pros and cons with eccentric bolt arms (whiteline) vs the threaded camber style like you currently have. I think the threaded camber style might be more geared for track considering they nearly all come with spherical bearings.

Threaded adjuster are super neat because you can figure out how much to turn to get X amount of change consistently and then you can make tweaks at the track on the fly.

Op your pictures don't tell me anything, check the torques, grab parts and shake them, make sure the springs are seated properly in the perches and hopefully that's it or it settles in.

Check the brackets on the anti roll bar are secure. I had a rear knock that I was struggling to find after fitting a set of coilovers. The left rear top bolt had become lose, causing the bracket to move under load which in turn caused a slight knocking noise when going over uneven surfaces.