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Discussion Starter · #1 ·
The H&R springs have been on my CLA for over 2 months now. But about 3 weeks ago I had the installer put back my Mercedes sports springs in the rear suspension because the H&R springs were making lots of creaking noises going over bumps and ruts.
Complained to H&R and they said for the CLA , customers have complained about this and their general fix is to provide rubber tubing to slide on the coils in the spring to allow for settling in of the new springs. But they can stay on without need to remove if desired.

So I just had my installer put it on for me , and the creaking noise is now pretty much gone. The ride is much better and definitely much stiffer than the Mercedes stock springs but still would not be considered harsh.

happy to see the reduction of the wheel gap again, the factory springs left a noticeable gap. Now the rear is exactly slightly less than 1.5 index finger gap.
 

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the spring ends rotate slightly with exercise so the noise would come from the top/bottom seat contacts ... and translate down the spring body and radiate away
so guess some rubber tube (but not at the seat contact pads) would damp the tuning fork effect
maybe thats why we see those on some cars ... my older one had them from the factory
a drop of silicone oil at the contact points also works sometimes but then needs replenishing
 

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Discussion Starter · #3 ·
the spring ends rotate slightly with exercise so the noise would come from the top/bottom seat contacts ... and translate down the spring body and radiate away
so guess some rubber tube (but not at the seat contact pads) would damp the tuning fork effect
maybe thats why we see those on some cars ... my older one had them from the factory
a drop of silicone oil at the contact points also works sometimes but then needs replenishing
Did the noise from the contact point rotation eventually go away after it had settled down and stopped rotating ?
 

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unless counter handed coils are used there will always be contact surface rub and some noise
so i guess damping the acoustics is the simple fix
every time i get home and park i bounce the corners ... quite happy how quiet the suspension still is
 

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Discussion Starter · #5 ·
the funny thing is, it only happened with the rear spring set up, the front strut H&R spring did not have any noise issue.
 

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Well you know how we roll ... if it works dont care how

If their solution works we are happy!
 

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Discussion Starter · #7 ·
Also, the ride seems less bouncy, especially at the rear suspension. When it was first installed 2 months ago, the ride seemed quite bouncy (but damped still). Now it is more pleasant over the rough roads.

But love the wheel gap now, generally no rubbing (even under hard cornering), unless I run over a speed bump without slowing down (which I WILL not attempt :))
 

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Discussion Starter · #8 ·
Okay, its been 3 months now (and over 2000km) since my H&R sport lowering springs was installed, the springs and shocks set up has now pretty much settled down, and the ride is definitely firm , cornering is very well controlled, aside from the small creak when going over speed bumps, overall pretty satisfied with it. The creak is probably coming from the tire touching the liner in fender, as the wheel gap is only about 1 pinky finger wide in the rear. Even though the front wheel gap is also about 1 pinky finger wide, it does not have this creaking sound when going over the speed bump.
 

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may not be the tire ... that room is supposed to accommodate full compression (like from a fly by and landing)
lately when i pull UP on the engine cover the suspension gets relieved for that split second ... and I hear this "eeeeekk"
holy crap the silence has broken ... dammit now i have to track it down
 

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Discussion Starter · #10 ·
may not be the tire ... that room is supposed to accommodate full compression (like from a fly by and landing)
lately when i pull UP on the engine cover the suspension gets relieved for that split second ... and I hear this "eeeeekk"
holy crap the silence has broken ... dammit now i have to track it down
What about bushings? It's definitely not the springs, as driving over regular roads, the car is very quiet from any spring compressionand relaxation noise. It's only when going over speed bumps, that the creak sound comes up at the rear. Maybe because of the stiffness of the springs, now some parts of the body has to take up some of the "shock", and creaks?? Still does not quite make sense...
 

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its high frequency “squeak” right?

for mine bouncing the corners is silent
but when relieving the springs something squeaks
hmmm ... might be the spring-perch joint
 

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Discussion Starter · #12 ·
its high frequency “squeak” right?

for mine bouncing the corners is silent
but when relieving the springs something squeaks
hmmm ... might be the spring-perch joint
Yes, regular driving on rough roads no issue... even the controlled bounce in cornering

But its when relieving the spring going over a speed hump, there's the creak you wear from a worn out spring, not sure if you know what I mean...

I was thinking about the spring perch point, ....

but honestly, it is much better now after allowing the spring set up to settle in... hopefully it will eventually taper off with time.
 
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