GL 450 front suspension mystery
#1
GL 450 front suspension mystery
Hello folks. Very new to the forum so please accept my apologies if this has been covered. My wife’s car a 2012 GL 450 w/ 60k is having a mystery suspension problem. It’s only occurring on front but there seems to be days where you come into the garage and it is a complete low rider after parking it an hour ago but then it can sit at the regular height for a week without dropping an inch. I haven’t pulled the tires and done the soapy water test due to that fact. The other weird part is youcan be driving highway speeds and it seems to dump everything out of the system all of the sudden and then fill back up again once you slow down or pull over.
Again I apologize if this has been covered but any help is greatly appreciated.
Again I apologize if this has been covered but any help is greatly appreciated.
Last edited by garettpage; 12-17-2017 at 03:00 PM.
#2
Senior Member
Joined: Sep 2005
Posts: 274
Likes: 54
From: s.f. bay area
s500 GL450 GL63 Z71XL Yukon 67 396 SS velle 68 Vert Camaro 69 RSSS Vert Camaro 75 Blazer
you most likely have a leak in your airbags. You are going to have to replace one if not both. depending on your mechanical skills and tools, it can be a job done in your garage for a lot cheaper than the dealer or garage. Also look up arnott for replacements. Also watch there video on replacing the airbag
#3
Can you clarify something? Does it occur for all 4 corners, or, front two only, or, front left or right only?
Has it been doing it for a while or just started?
Has it been doing it for a while or just started?
Hello folks. Very new to the forum so please accept my apologies if this has been covered. My wife’s car a 2012 GL 450 w/ 60k is having a mystery suspension problem. It’s only occurring on front but there seems to be days where you come into the garage and it is a complete low rider after parking it an hour ago but then it can sit at the regular height for a week without dropping an inch. I haven’t pulled the tires and done the soapy water test due to that fact. The other weird part is youcan be driving highway speeds and it seems to dump everything out of the system all of the sudden and then fill back up again once you slow down or pull over.
Again I apologize if this has been covered but any help is greatly appreciated.
Again I apologize if this has been covered but any help is greatly appreciated.
#4
#5
MBWorld Fanatic!
Joined: Nov 2017
Posts: 1,218
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From: Bethesda, MD
2010 Mercedes GL450; 2000 Mercedes ML55 AMG; 2016 VW GLI SEL Stick!!!
You have a leak. Albeit it could be a small one or a large one...it is guesswork until you do a proper soapy water test.
I imagine your leak is up in the higher parts of the air spring, as from what you're saying it doesn't happen so often. This would mean it's usually covered and plugged but some jolt bump or certain elongation of the spring can cause it to leak out.
Replace and figure it out soon though, as you're only causing more and more damage to your compressor.
#6
you most likely have a leak in your airbags. You are going to have to replace one if not both. depending on your mechanical skills and tools, it can be a job done in your garage for a lot cheaper than the dealer or garage. Also look up arnott for replacements. Also watch there video on replacing the airbag
I also have Arnotts on the way.
-Mel
#7
MBWorld Fanatic!
Joined: Nov 2017
Posts: 1,218
Likes: 149
From: Bethesda, MD
2010 Mercedes GL450; 2000 Mercedes ML55 AMG; 2016 VW GLI SEL Stick!!!
I had my rear airbags and the compressor replaced last year at the dealer. Now one of my front airbags has taken a hit. This time I plan to replace both front bags on my own. I'm fairly handy with tools. My problem has always been having the right tools. Can you give me a list of tools needed? Socket sizes, wrenches, etc. I already have a ball joint separator on the way per your suggestions in a different thread.
I also have Arnotts on the way.
-Mel
I also have Arnotts on the way.
-Mel
I hope you ordered the full unit for the front instead of just the airbags. Youll save yourself plenty of trouble and time is you just do the full shock and air spring unit in one go
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#8
This time I plan to replace both front bags on my own. I'm fairly handy with tools. My problem has always been having the right tools. Can you give me a list of tools needed? Socket sizes, wrenches, etc. I already have a ball joint separator on the way per your suggestions in a different thread.
Don't drop the caliper when it's free. Nothing like seeing a caliper dangling on kinked hydraulic lines. I literally got a brake line to later rupture once doing that, though it was a plastic / steel braided line and not the fiber reinforced rubber.
Ignore Arnott's instructions to change the air fitting. You can always change it later if it leaks, and you cause yourself all kinds of possible grief damaging the air line getting the fitting off.
Change your stabilizer links while you're in there. They are a frail part and make mysterious knocking noises on entering driveways, etc. They are cheap and you will have the job half done already anyway.
The one super important tip is to compress the struts and hold them closed with wire or string before putting into position. That is the one part of the job that made me cry for not knowing This One Simple Tip.
#9
Bingo. I thought of that method about 30 seconds AFTER I struggled with getting both the old one out and the new one in, along with the axle popping out a few times along the way. I finally got it all back together and paused... and thought... This is the exact thought that went through my head: "Wait, couldn't I have just... Idiot".
#10
Bingo. I thought of that method about 30 seconds AFTER I struggled with getting both the old one out and the new one in, along with the axle popping out a few times along the way. I finally got it all back together and paused... and thought... This is the exact thought that went through my head: "Wait, couldn't I have just... Idiot".
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eric_in_sd (12-22-2018)
#11
The one thing I found very easy to work with is ratcheting Tie down to compress the strut. Sorry I should have taken picture when I did mine.
The non ratcheting kind doesn't come apart to a free end like that.
#12
Well last weekend I took a stab at replacing the air spring. Thanks to all the tips from you all, I was able to get them installed fairly easy. We've been riding on them for a week now with no issues. No more mornings coming to the truck and seeing a front corner drooping.
I would agre@kombifan about replacing the entire unit. Not necessarily because of the time though (taking the old shock off and installing the arnott version was probably the easiest part of it all). In the written instructions it says to check the shocks. If there is excessive leaking, you should replace the whole unit. I'm not sure what symptoms would have shown that leads you to know the shock is busted and needs to be replaced, without taking the air spring off.?
Either way, the shocks were in good working order.
It sure feels good to save so much money on parts and labor!
I would agre@kombifan about replacing the entire unit. Not necessarily because of the time though (taking the old shock off and installing the arnott version was probably the easiest part of it all). In the written instructions it says to check the shocks. If there is excessive leaking, you should replace the whole unit. I'm not sure what symptoms would have shown that leads you to know the shock is busted and needs to be replaced, without taking the air spring off.?
Either way, the shocks were in good working order.
It sure feels good to save so much money on parts and labor!
#13
I have an update.
First, the ride quality of the new Arnott shocks is unbelievable. We took a 2000mi round trip to Disney World last week and the GL rode like a dream. It even seems like the ride height adjusts to/from highway speeds quicker. Before the replacement, you could notice the truck lifting back up after getting off an exit from the interstate. Now it's seamless.
Although the ride is much smoother, I'm noticing a rattling sound that seems to come from the front passenger side of the truck. It's a heavy rattle like the sound you'd hear when the hood isn't latched all the way (I've checked and I wish the problem was that simple).
I did some tests: The rattling sound is not heard at highway speeds when the truck lowers and it's not heard when the truck is raised all the way up. I've rechecked the control arm bolts - everything is impact wrench tight. During the shock replacement, nothing snapped or broke as far as I could tell. The steering works great with no vibrations or knocking. I'm clueless!
Any ideas?
-Mel
First, the ride quality of the new Arnott shocks is unbelievable. We took a 2000mi round trip to Disney World last week and the GL rode like a dream. It even seems like the ride height adjusts to/from highway speeds quicker. Before the replacement, you could notice the truck lifting back up after getting off an exit from the interstate. Now it's seamless.
Although the ride is much smoother, I'm noticing a rattling sound that seems to come from the front passenger side of the truck. It's a heavy rattle like the sound you'd hear when the hood isn't latched all the way (I've checked and I wish the problem was that simple).
I did some tests: The rattling sound is not heard at highway speeds when the truck lowers and it's not heard when the truck is raised all the way up. I've rechecked the control arm bolts - everything is impact wrench tight. During the shock replacement, nothing snapped or broke as far as I could tell. The steering works great with no vibrations or knocking. I'm clueless!
Any ideas?
-Mel
#14
Stabilizer links. Much to my chagrin, I got Arnott to replace a strut because a knocking sound appeared shortly after the strut was installed. It turned out that the replacement disturbs the stabilizer links, which don't like their nap interrupted; the strut was fine.
There are multiple possible causes, but the stabilizer links seem to be by far the most common. In addition, they are cheap to buy and cheap to install.
There are multiple possible causes, but the stabilizer links seem to be by far the most common. In addition, they are cheap to buy and cheap to install.
#15
Agree - first, and most likely, culprit are the end links. But I'm not sure I would refer the sound as "rattling" - it's more of a knocking sound. They seem to go bad every few years. Not sure why they can't be made to last longer. Lift the front end, with the weight off the suspension and get your hand on the link - push, pull, HARD, etc - see if you can duplicate. Sometimes it tough to duplicate by hand - until they get really bad. There's not a whole lot of suspension stuff under there - try the push/pull thing with other parts, too.
#16
MBWorld Fanatic!
Joined: Nov 2017
Posts: 1,218
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From: Bethesda, MD
2010 Mercedes GL450; 2000 Mercedes ML55 AMG; 2016 VW GLI SEL Stick!!!
+1 on endlinks. I replaced all 4 recently and it go rid of al my knocking noises and vibration feedback in the steering wheel.
I went for lemforder and rein. Fcp euro 😝
I went for lemforder and rein. Fcp euro 😝
#17
Ok. I can check stabilizer links. The steering wheel does not vibrate though, and neither does the truck.
I attached a video clip from last night as I was driving down my street. In about the first 10 seconds, you can hear the rattle.
-Mel
I attached a video clip from last night as I was driving down my street. In about the first 10 seconds, you can hear the rattle.
-Mel
#18
I've personally never heard an end link sound like that - it's the "continuous" rattling (multiple in quick, short succession) that sounds different to me. I suppose if the link was REALLY shot? Either way, get underneath and touch and feel everything.
Didn't leave a tool in there somewhere, did you?
For what it's worth, I've never felt a vibration in the steering wheel when I've had a bad link - but maybe I have just replaced them early enough, before they start acting up that bad. Heck, I think I have a bad one right now - no vibration of any kind - just an annoying knock going over some bumps.
Didn't leave a tool in there somewhere, did you?
For what it's worth, I've never felt a vibration in the steering wheel when I've had a bad link - but maybe I have just replaced them early enough, before they start acting up that bad. Heck, I think I have a bad one right now - no vibration of any kind - just an annoying knock going over some bumps.
#19
Dennis I can feel the knocking in the steering. I'm pretty sensitive, though, having spent most of my miles in cars that need constant attention. It's faint, like a pressure wave finding its way up the steering system.
Mel that's way higher pitched than the knocking I hear from my loose links. Outside the car they're way higher pitched, but inside it's more like thumps from the belly of the beast. I'm baffled; it sounds like lug nuts rattling inside a hubcap. I'm having a hard time imagining what it would be. Something is flailing around down there. On the plus side, that can't be too hard to find; jack it up, or even just lift it on the air springs, and push and pull on stuff.
Heck, fighter pilots go around their birds and wiggle stuff before takeoff.
Mel that's way higher pitched than the knocking I hear from my loose links. Outside the car they're way higher pitched, but inside it's more like thumps from the belly of the beast. I'm baffled; it sounds like lug nuts rattling inside a hubcap. I'm having a hard time imagining what it would be. Something is flailing around down there. On the plus side, that can't be too hard to find; jack it up, or even just lift it on the air springs, and push and pull on stuff.
Heck, fighter pilots go around their birds and wiggle stuff before takeoff.
#20
All tools accounted for.
Stabilizer links look good to me. Shaking things in the wheel well didn't help much - not sure that I can equal the weight of the truck on the road.
Pics attached. While I've got it jacked up, any other thoughts. What does a worn link look like?
Could it be bad ball joints or tie rods?
Stabilizer links look good to me. Shaking things in the wheel well didn't help much - not sure that I can equal the weight of the truck on the road.
Pics attached. While I've got it jacked up, any other thoughts. What does a worn link look like?
Could it be bad ball joints or tie rods?
Last edited by DrMel; 01-04-2019 at 03:11 PM.
#21
Will take a better look at pics later, but a worn link won't "look" bad (unless it's really bad). You gotta (weight off wheel) really push and pull hard - even use a bar to get more leverage on things. Look/listen/feel for any clicking. It won't be as "heavy" sounding as when the vehicle is in use. I'm not saying it IS the links, but that's way to check them 95%. Sometimes it's an educated guess if you can't replicate it.
EDIT: Just adding a quick thought... You said that the rattling ONLY occurs when at normal ride height. Did the sound ACTUALLY go away at highway speeds, or was it just because you may not be able to hear it anymore? When you raise the vehicle, and drive around town, the noise disappears, but when driving the same roads at normal hieght the sound comes back? It's gotta be something in the air spring itself, or the suspension.
EDIT: Just adding a quick thought... You said that the rattling ONLY occurs when at normal ride height. Did the sound ACTUALLY go away at highway speeds, or was it just because you may not be able to hear it anymore? When you raise the vehicle, and drive around town, the noise disappears, but when driving the same roads at normal hieght the sound comes back? It's gotta be something in the air spring itself, or the suspension.
Last edited by DennisG01; 01-04-2019 at 05:01 PM.
#22
Will take a better look at pics later, but a worn link won't "look" bad (unless it's really bad). You gotta (weight off wheel) really push and pull hard - even use a bar to get more leverage on things. Look/listen/feel for any clicking. It won't be as "heavy" sounding as when the vehicle is in use. I'm not saying it IS the links, but that's way to check them 95%. Sometimes it's an educated guess if you can't replicate it.
EDIT: Just adding a quick thought... You said that the rattling ONLY occurs when at normal ride height. Did the sound ACTUALLY go away at highway speeds, or was it just because you may not be able to hear it anymore? When you raise the vehicle, and drive around town, the noise disappears, but when driving the same roads at normal hieght the sound comes back? It's gotta be something in the air spring itself, or the suspension.
EDIT: Just adding a quick thought... You said that the rattling ONLY occurs when at normal ride height. Did the sound ACTUALLY go away at highway speeds, or was it just because you may not be able to hear it anymore? When you raise the vehicle, and drive around town, the noise disappears, but when driving the same roads at normal hieght the sound comes back? It's gotta be something in the air spring itself, or the suspension.
#23
Senior Member
Joined: Jan 2017
Posts: 253
Likes: 60
From: Houston, TX
Mercedes Benz 2007 GL450 , 2012 BMW 528i
It doesn't sound like end links to me.
I would still replace them since they are cheap, even if just to check if that was it. But if you want to be certain, you can disconnect endlinks, drive and check for rattle. A vehicle can be driven with end links disconnected as long as you don't go crazy at curves.
Did you check steering column linkage?
I would still replace them since they are cheap, even if just to check if that was it. But if you want to be certain, you can disconnect endlinks, drive and check for rattle. A vehicle can be driven with end links disconnected as long as you don't go crazy at curves.
Did you check steering column linkage?
#24
Few know this. Fine to drive; just don't go hard into a curve. It will oversteer like you won't believe.
#25
I finally had a chance to replace end links. Very quick and easy task.
Unfortunately, the heavy rattle is still there... but at least I won't have to worry about the end links again for a while.
At this point, I'm pretty confident it's coming from the front passenger side.
I'm starting to think it's bushing related, just not sure which ones.
Unfortunately, the heavy rattle is still there... but at least I won't have to worry about the end links again for a while.
At this point, I'm pretty confident it's coming from the front passenger side.
I'm starting to think it's bushing related, just not sure which ones.