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I am getting a clunk/squeek from the driver rear and during my investigation, I believe it's coming from the rear sway bar bushing. The driver side one looks more brittle and has more gaps than the passenger side one.
I can't seem to find a replacement for the bushing itself. Is it not possible to replace it...does the entire sway bar need replaced?
Where can I find the bushing if it can be replaced?
Attached is an example of what I'm referring to. The darker photo is my actual bushing.
Crawl underneath with a spray can of silicone. Not WD-40 or other petroleum based lube, but silicone. Spray the swaybar bushings - where the bushing meets the bar - and see if that fixes the squeak. Next candidate is the control arm bushings.
The swaybar bushings on the front, as well as all the control arm bushings, depend on stretching and twisting the bushing to deflect the suspension. This is a retarted design for high suspension travel (i.e. off road) vehicles, but that's life with MB. (For off-road applications, if you are serious, you get actual bearing inserts for the control arms.) For the swaybars, you can just not install the bolts that clamp the bushing to the swaybar. I don't know and can't tell from your pictures whether the rear swaybar bushings are of the same design as the front. Even if the bushings have come apart, I wouldn't replace them unless the swaybar starts clunking around inside what used to be the bushing.
If this were a performance vehicle I'd worry about the bushings, but it's a freakin truck.
If you decide you simply must replace the rear swaybar bushings, someone can look them up on EPC.
It doesn't look like they are meant to be replaceable, so probably not available.
Attached are for my 08 gl320.
Yea, currently looking to replace the bar if the recommendation for spraying them doesn't help above. When I was doing my test last night, it just seemed like you could see the bar move inside the bushing a bit.
I'll likely just find a used one off Ebay since a new one (also off Ebay...these sway bars are hard to find) are like $400+
Crawl underneath with a spray can of silicone. Not WD-40 or other petroleum based lube, but silicone. Spray the swaybar bushings - where the bushing meets the bar - and see if that fixes the squeak. Next candidate is the control arm bushings.
The swaybar bushings on the front, as well as all the control arm bushings, depend on stretching and twisting the bushing to deflect the suspension. This is a retarted design for high suspension travel (i.e. off road) vehicles, but that's life with MB. (For off-road applications, if you are serious, you get actual bearing inserts for the control arms.) For the swaybars, you can just not install the bolts that clamp the bushing to the swaybar. I don't know and can't tell from your pictures whether the rear swaybar bushings are of the same design as the front. Even if the bushings have come apart, I wouldn't replace them unless the swaybar starts clunking around inside what used to be the bushing.
If this were a performance vehicle I'd worry about the bushings, but it's a freakin truck.
If you decide you simply must replace the rear swaybar bushings, someone can look them up on EPC.
If a control arm bushing has play in it, the vehicle handling becomes sloppy. Play in the swaybar bushings only means that the vehicle handling as you turn harder does not respond as linearly as it might. It is very subtle. The bushing is designed to have play so that the vehicle understeers when you begin the turn, then understeers less as the rear bushings compress and the swaybar goes to metal on metal. Get the picture? If you really cared about handling, you would install solid bearings.
Fixing this would be so far down on my list of priorities, we're talking Mariana Trench depths. But you do you.
If the spray silicone fixes the squeak, you can apply some silicone grease for longer life. You probably would have to unbolt the bushings and slide them to the side (clean the bushings and bar first) to effectively apply the grease.
There is no reason to expect a used Ebay swaybar's bushings would be in any better shape.
The rear control arm bushings are a far more likely culprit for the squeak. @alx said the suspension height doglegs can squeak too. idk. No one ever talked about the swaybar bushings before. You're the first. Let us know what you find out.
If a control arm bushing has play in it, the vehicle handling becomes sloppy. Play in the swaybar bushings only means that the vehicle handling as you turn harder does not respond as linearly as it might. It is very subtle. The bushing is designed to have play so that the vehicle understeers when you begin the turn, then understeers less as the rear bushings compress and the swaybar goes to metal on metal. Get the picture? If you really cared about handling, you would install solid bearings.
Fixing this would be so far down on my list of priorities, we're talking Mariana Trench depths. But you do you.
If the spray silicone fixes the squeak, you can apply some silicone grease for longer life. You probably would have to unbolt the bushings and slide them to the side (clean the bushings and bar first) to effectively apply the grease.
The rear control arm bushings are a far more likely culprit for the squeak. @alx said the suspension height doglegs can squeak too. idk. No one ever talked about the swaybar bushings before. You're the first. Let us know what you find out.
That noise you hear happens when just driving straight. No turning or anything. Just anytime I'm going over slopes in the road, bumps, etc.. from the drivers seat it sounds like like a clunk/knock type noise in that driver side rear area. So while I don't 100% know if that noise (in the video) IS the sway bar bushing, when I moved the camera closer to say the Sway bar Link, the noise sounded less loud.
Maybe I will try the silicone route and see if that helps dampen the noise. I can also try to investigate the control arm bushings. To me, it's not a squeak, more of a clunk/knock which then has a squeak associated.
I almost wondered if it was the 'hat' of the strut moving each time the suspension raised and lowered over hills/bumps.
If a control arm bushing has play in it, the vehicle handling becomes sloppy. Play in the swaybar bushings only means that the vehicle handling as you turn harder does not respond as linearly as it might. It is very subtle. The bushing is designed to have play so that the vehicle understeers when you begin the turn, then understeers less as the rear bushings compress and the swaybar goes to metal on metal. Get the picture? If you really cared about handling, you would install solid bearings.
Fixing this would be so far down on my list of priorities, we're talking Mariana Trench depths. But you do you.
If the spray silicone fixes the squeak, you can apply some silicone grease for longer life. You probably would have to unbolt the bushings and slide them to the side (clean the bushings and bar first) to effectively apply the grease.
There is no reason to expect a used Ebay swaybar's bushings would be in any better shape.
The rear control arm bushings are a far more likely culprit for the squeak. @alx said the suspension height doglegs can squeak too. idk. No one ever talked about the swaybar bushings before. You're the first. Let us know what you find out.
Attached are 3 photos. 2 are of the passenger rear bushings (outer view, inner view) which their condition looks good. The other is the driver rear (similar to the original photo in my post) but shows a more worn down condition.
Funny, they want to charge you $400 when what you need to replace is a fifty cent piece of rubber.
I seriously doubt you would notice any handling difference if you replaced those with new. Even if the one is good and shredded.
If you want to test how worn they are, put a pry bar between the bar and the rear sub-frame, between the two bushings. See how easily the bushing compresses, and whether it compresses more on one side versus the other when the same force is applied.
You might also look into whether anyone makes performance oriented rear bushings. The vehicle would oversteer a little more, but if you aren't racing you probably would not notice the difference.
It is curious that the bar gripped the rubber hard enough to tear it. Now, if they had been assembled with silicone grease in the first place, this never would have happened.
any handling difference if you replaced those with new. .
Thing is, I'm not noticing handling issues. Granted, I'm not a car expert so not sure if I would notice if I was. I've just been noticing the super obvious 'clunk' when driving down my neighborhood street, let alone city roads and the highway.
I've seen some people use polyurethane / 3m window weld to fix bushing issues...maybe it would be worth trying to inject some into that space I'm seeing in the 'bad' bushing.
I agree, I don't want to mess with the bar, especially a used 2010 bar and definitely not a $400 one.
Still, a spritz of silicone spray is cheaper than $35 bushings. If all you care about is the squeaking, I'b be tempted to just take apart the bushings and put silicone grease inside.
But you also still don't know whether it is the swaybar bushings that are squeaking. You are fixated on them because one of them looks to have degraded. If that's how the swaybar bushings look, imagine what the control arm bushings look like. They are much more heavily stressed.
Still, a spritz of silicone spray is cheaper than $35 bushings. If all you care about is the squeaking, I'b be tempted to just take apart the bushings and put silicone grease inside.
But you also still don't know whether it is the swaybar bushings that are squeaking. You are fixated on them because one of them looks to have degraded. If that's how the swaybar bushings look, imagine what the control arm bushings look like. They are much more heavily stressed.
Best wishes to you in your adventure.
Thank you. Yes, I will investigate further. Does that mental clamp (with the 2 bolts) actually come off the top of the bushing to where I could remove the old one?
It looks to me like the two pieces are swaged together. So they'll need to be drilled or ground out to separate.
Thanks Mercedes. LOL.
Yea, I might try to go with the grease route first rather than trying to separate IF this IS the cause of the noise. As Eric said, could be other things.
@gb25 Good find. Amazing the lengths MB would go to in their quest to lower assembly cost. They had the subcontractor deliver the rear swaybars with bushings permanently attached. I wonder why they didn't do the same with the front swaybar. I also wonder why they clamped the front bushing to the bar, but that is a different issue. MB's engineering is hit or miss.
@majorchamp No matter, that is why God made step drill bits. Ordinary twist drill not recommended. Go slow, oil the hole, and test frequently. Wash the oil off the brackets afterward or it will decay the precious new bushings. After you separate the two parts of the bracket, investigate whether to reuse the flat part. If the curved part's flanges are flush with the flat part of the bushing after drilling out or grinding off the swage remnants, I'd be sorely tempted to get rid of the flat piece. For this application, vehicles have used simple one-piece curved brackets with flat bases for ages. It all depends on your confidence with metal.
Having spent this much time thinking about the situation, I am tempted to do this bushing replacement just to investigate and document.
Last edited by eric_in_sd; Feb 17, 2024 at 11:03 AM.
@gb25 Good find. Amazing the lengths MB would go to in their quest to lower assembly cost. They had the subcontractor deliver the rear swaybars with bushings permanently attached. I wonder why they didn't do the same with the front swaybar. I also wonder why they clamped the front bushing to the bar, but that is a different issue. MB's engineering is hit or miss.
@majorchamp No matter, that is why God made step drill bits. Ordinary twist drill not recommended. Go slow, oil the hole, and test frequently. Wash the oil off the brackets afterward or it will decay the precious new bushings. After you separate the two parts of the bracket, investigate whether to reuse the flat part. If the curved part's flanges are flush with the flat part of the bushing after drilling out or grinding off the swage remnants, I'd be sorely tempted to get rid of the flat piece. For this application, vehicles have used simple one-piece curved brackets with flat bases for ages. It all depends on your confidence with metal.
Having spent this much time thinking about the situation, I am tempted to do this bushing replacement just to investigate and document.
fwiw, one of the Ebay postings I looked at for a used sway bar (IF I go that route) I had them send over a few more pics for comparison. These came off a 2010 GL
Still, a spritz of silicone spray is cheaper than $35 bushings. If all you care about is the squeaking, I'b be tempted to just take apart the bushings and put silicone grease inside.
But you also still don't know whether it is the swaybar bushings that are squeaking. You are fixated on them because one of them looks to have degraded. If that's how the swaybar bushings look, imagine what the control arm bushings look like. They are much more heavily stressed.
Best wishes to you in your adventure.
I did buy some silicone spray...I've not used it yet. How do you feel about this being pushed into some of those bushing gaps?
That only makes sense if you're trying to restore the bushing to restore handling. You (correctly, imo) don't care about handling. To be honest, you could take off the swaybar entirely. That is likely what a rally driver would do. You'd get a bit more body roll and a bit more understeer.
Spritz the silicone inside. You'll want a layer of silicone lubricant in there in case you want to put silicone rubber, e.g. Permatex, in there. You could put in any silicone rubber caulk, by the way. For this application, anyway.
That only makes sense if you're trying to restore the bushing to restore handling. You (correctly, imo) don't care about handling. To be honest, you could take off the swaybar entirely. That is likely what a rally driver would do. You'd get a bit more body roll and a bit more understeer.
Spritz the silicone inside. You'll want a layer of silicone lubricant in there in case you want to put silicone rubber, e.g. Permatex, in there. You could put in any silicone rubber caulk, by the way. For this application, anyway.
Gotcha.
So my investigation continues. I'm seeing what I think is a 'leaking' shock. I replaced my rear shocks (Arnott SK-2868)(and air springs) in June 2020. I think I've only put around 30k miles on the vehicle. The passenger rear does NOT look like this (yellow residue).
I feel like the squeak IS coming from one of those bushings...but the 'knock' is coming from the top of the shock. A part of me wonders if that is a normal noise for a failed shock...or the top shock where it is bolted to the body (under the 3rd row arm rest) is loose. That is how I installed the rear shocks was going through the 3rd row arm rest, per a 'hack' I read on these forums.
What throws me off, a bit, is the 'knock' seems to sound louder when I have the camera near the rear sway bar bushing (which is why I thought that was the culprit) vs when I'm pointing it elsewhere like the top of the shock.
Anyways, here are 2 videos of the shock. So now I'm leaning toward replacing them again. I'm also adding that 3rd 'bushing' video as well for comparison.
Get under there with a stethoscope. The clunk could be the swaybar shifting within the rotted bushing and impacting the bracket. This should only happen when the vehicle is rocking, such as when your helper pushes on the roof rails.
In my opinion you are devoting too much energy to diagnosis when the part is just $35 and can be replaced without a huge amount of labor.
What's all that orange goo dripping down the shock?
Most people just install Bilstein shocks. Are those Arnott shocks made by Bilstein?
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