Help identifying the culprit in a squeaky suspension w/ video
ARB bushes are a very common driver of unwanted noise on all cars, as the bush ages and becomes less flexible, it also tends to shrink back leading to unwanted movement, noises and reduced roll control (not sway !!!!). And with lots of age you get knocking as the ARB rattles in the bushes, with W221 tank being so heavy it came with truck spec parts and tens to squeak and graunch rather than rattle
ARB bushes are a very common driver of unwanted noise on all cars, as the bush ages and becomes less flexible, it also tends to shrink back leading to unwanted movement, noises and reduced roll control (not sway !!!!). And with lots of age you get knocking as the ARB rattles in the bushes, with W221 tank being so heavy it came with truck spec parts and tens to squeak and graunch rather than rattle
if you intend to get new bushes fitted (fleabag sell fakes you can try and fit to an old ARB) then you can just squirt lube on them and see if the noise goes away ?
if you intend to get new bushes fitted (fleabag sell fakes you can try and fit to an old ARB) then you can just squirt lube on them and see if the noise goes away ?




These suspensions with the double lower control arms are difficult to check for wear on these ball joints as it is darn near impossible to move the ball joints for wear inspection by hand force. You really need to remove one of the arms to do a good inspection.
This problem got me with my car as I was troubleshooting the noise. Both sides ball joints felt tight by normal "grab the wheel and rock it sideways" test but I saw the passenger side rearward ball join rubber broken so I ordered the part and replaced it. Problem got little better but was not fixed. Trying to rock the drives side wheel by hand again to feel any ball joint wear was impossible so I removed the rearward arm and it was very clear that the ball joint was totally worn out though the rubber was good. So, ordered the arm and replaced it. No more "chirping".
These suspensions with the double lower control arms are difficult to check for wear on these ball joints as it is darn near impossible to move the ball joints for wear inspection by hand force. You really need to remove one of the arms to do a good inspection.
This problem got me with my car as I was troubleshooting the noise. Both sides ball joints felt tight by normal "grab the wheel and rock it sideways" test but I saw the passenger side rearward ball join rubber broken so I ordered the part and replaced it. Problem got little better but was not fixed. Trying to rock the drives side wheel by hand again to feel any ball joint wear was impossible so I removed the rearward arm and it was very clear that the ball joint was totally worn out though the rubber was good. So, ordered the arm and replaced it. No more "chirping".
Last edited by COUPCONNOISSEUR; Mar 5, 2022 at 10:37 PM.
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Last edited by COUPCONNOISSEUR; Jul 16, 2022 at 05:30 PM.



Why didn't you change the Lower Control Arm, the likely cause of the squeaking?



Last edited by COUPCONNOISSEUR; Jul 16, 2022 at 06:36 PM.
These suspensions with the double lower control arms are difficult to check for wear on these ball joints as it is darn near impossible to move the ball joints for wear inspection by hand force. You really need to remove one of the arms to do a good inspection.
This problem got me with my car as I was troubleshooting the noise. Both sides ball joints felt tight by normal "grab the wheel and rock it sideways" test but I saw the passenger side rearward ball join rubber broken so I ordered the part and replaced it. Problem got little better but was not fixed. Trying to rock the drives side wheel by hand again to feel any ball joint wear was impossible so I removed the rearward arm and it was very clear that the ball joint was totally worn out though the rubber was good. So, ordered the arm and replaced it. No more "chirping".
I’m not going to do it myself cause I’m just not than young any more, but I do have a couple questions.
Do you have any recommendations for where to get the replacement control arms? One can buy a pair of control arms for under a hundred bucks on eBay. Are they any good?
Should the front end be realigned after the control arms are installed?
Thanks a bunch!
I’m not going to do it myself cause I’m just not than young any more, but I do have a couple questions.
Do you have any recommendations for where to get the replacement control arms? One can buy a pair of control arms for under a hundred bucks on eBay. Are they any good?
Should the front end be realigned after the control arms are installed?
Thanks a bunch!
Last edited by COUPCONNOISSEUR; Jan 10, 2023 at 10:21 AM.
I've ordered a pair of TRQ rearmost lower control arms for about $140. (One OEM control arm was over $300)
The local tire store that provided the new Michelin's and did the alignment gave me a bid for $300 to install both arms and another $89 to realign.
I'll report back after the parts are installed. Fingers crossed.




I've ordered a pair of TRQ rearmost lower control arms for about $140. (One OEM control arm was over $300)
The local tire store that provided the new Michelin's and did the alignment gave me a bid for $300 to install both arms and another $89 to realign.
I'll report back after the parts are installed. Fingers crossed.
In my car there is no alignment other than the toe adjustment if needed. The arms fit in place one way and there is nothing else to move for alignment. There are some after market bolt kits available for other than toe adjustment but as the car comes from the manufacturer there is no adjustments for alignment in front or rear other than that front toe.
Last edited by Arrie; Jan 10, 2023 at 07:37 PM.




In my car there is no alignment other than the toe adjustment if needed. The arms fit in place one way and there is nothing else to move for alignment. There are some after market bolt kits available for other than toe adjustment but as the car comes from the manufacturer there is no adjustments for alignment in front or rear other than that front toe.
He suggested and said he had good luck with a brand (don't recall) of control arm that uses a metallic rather than a rubber bushing. He claims they will never wear out.
Considering the TRQ control arms arrive tomorrow and because I don't want to give up any of the inherent S Class smoothness, I'm going to use rubber bushings.
The alignment seems OK, but it's been a few years so I think I'll have the alignment checked.
Thanks for the advise!




He suggested and said he had good luck with a brand (don't recall) of control arm that uses a metallic rather than a rubber bushing. He claims they will never wear out.
Considering the TRQ control arms arrive tomorrow and because I don't want to give up any of the inherent S Class smoothness, I'm going to use rubber bushings.
The alignment seems OK, but it's been a few years so I think I'll have the alignment checked.
Thanks for the advise!
The shop owner said he had the best alignment man in the county. I have to say the car does seem to track just a bit truer. They also provided me with a complete printout of before and after readings.
I'm well pleased, and appreciate the wisdom on this forum!







