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Hey.. Since the rear torsion bar comes with the bushings glued to the bar does that mean the bar should only flex in bushing and NOT rotate up and down.. Just looking for confirmation..
but your post title was torsion bar which is used in suspensions as a spring (normally independent suspension front ends of trucks) hence the confusion.
IT is a bar that is twisted aka torqued aka torsional spring
Sorry did not know the Germans call it that in their parts book.
All my life here in USA we call it ANTI-SWAY bar.
See how nomenclature can confuse peeps as well as all those abreviations.
Are you sure it is glued and not just oldlubriction?
Prupose of Sway bar is to resist body roll as car is turned.
The outside body side will try to go down and the other side will try to lift.
This difference moves one side of sway bar end down and the other side up as the body rolls
So the bar in the middle gets twisted aka TORQUEDor Torsional loaded
This twist is a way to transmit a force from one side to the other side to resist this body roll.
Twisting a bar cues angular rotation of bar from one end to the other which is why normally manufacturers want you to put grease on bar and inside bushing when installing.
Heck some aftermarket upgraded ones have grease fittings on the bushing bracket, others give you that little sample of grease.
Never heard of GLUE as it would break loose over time and many twists back and forth.
That's exactly why I'm asking the original question.. There are no bushings that can be ordered.. They only come glued or cemented to the bar. The entire bar has to be ordered.. The front bar has removable bushings but no the back.. Thats why Mercedes calls it a torsion bar..
Well I did not know MB was selfish and did not make the bushings a WEAR item like just about every other manufacturer.
They need to be replaceable.
MAking an owner replace entire bar is Crazy and way more expensive if done in repair shop. more parts and labor.
SO MB makes you WASTE money and throw away a perfectly good steel sway bar (think environmental concerns for those who care a great deal)
Old bar goes to scrap heap and hopefully recycled but why?
What is their logic behind this design?
Bars can fatigue but way way after you gone thru a few sets of bushings.
anyways I read this thread before this one today and now you r original post makes sense -
I apologize for not looking into it but I thought MB would be like every other manufacturer out there.
Maybe do what this guy did to front - Remove bar and remove bushing bracket thingys and then cut off old bushing.
Buy some aftermarket new bushings online and Cut flat base apart and slip over bar and reinstall those MB metal clips and reinstall bar.
Add grease to reduce noise and prolong life (silicone grease is best on rubber)
I wonder if someone makes them out of stiffer poly-urethane - stiffer ride but less body roll.
I agree that it's a unfriendly design.. So here is the question.. Since the rear bushings are attached to the bar and the torque spec is 60ft lbs that sounds like the bar should not rotate but only flex as a torsion bar with the bushing.. You agree?
And the front bar has changeable unattached bushings with only a torque spec of 22ft lbs that sounds like front bar does rotate up and down and acts like a true sway bar..
bar has to torque over entire length..
unless it bar was KEYED or WELDED to the mounts and if that was case they would not have rubber bushings.
I bet those rubber bushings can be replace if it can be unbolted look at the bushing clamp brackets and see if they can be removed. if they can then easy to get old rubber bushing off with knife.
Some how they had to install them.
I see a line on the rubber like it is split along length.
WOuld love to have hands on one to inspect and see if the bushings could be removed.
Just wonder if anyone in aftermarket makes them?
And I cannot see any glue holding up to the torsional loading a sway bar can see.
Look at pic I found on ebay; I see gap around bar between rubber bushing.
That is one weird mounting bracket. most manufacturers just stamp out a C clamp that holds bushing in place and bolts to chassis or body somewhere.
From pure physics and engineering look the pull down on one side is transmitted thru bar as TORQUE and is not resisted at bushings but by other end so torque travels entire length from one end to other and is twisted in between pretty evenly what we call angular rotation and the sway bar has so much Force per degree twist which can be converted into a spring rate.
Just could not see why they would glue other then to hold them in position for install.
Terrible design for the DIY selfer like me.. One thing I have to add.. The reason I posted this is because of this.
I bought this car just under a year ago. It only has 79,000 miles and is in near showroom condition. Came out of Arizona only one owner. Not a single drop of rust.. So only problem it has is this . When I bought it the right rear only over heavy bumps or a series of bumps it sounded like the right rear shock was hitting the underside of car or maybe the sway bar.. As I am into performance I changed all the suspension front and back to H&R Springs with Bilstien B8, s.. I changed both upper rear shock mounts(Bilstein mounts) New upper spring mounts , sway bar end links and couple of the control arms.. The noise still there.. All the bushings are in good condition. Well after re-torqueing everything and climbing underneath car many many times I found that torqueing the sway bar to 80ft lbs rather then 60ft lbs (Mercedes spec) the noise or thump happens way less but does still happen.. I've looked for any marks where the sway bar could come into contact with the underside but nothing there . That's the reason I asked about the bar being in a fixed position.. I was thinking if the "glue" separated from the bushings to bar that maybe the bar was rotating and causing the thump . When the bar is tightened more you can definitely feel the rear of the car tighter and actually handles better.. By the way this car does not have the air ride and does have the AMG sport package... And yes everything was installed and torqued at ride height..
I would say if you dont see any rub or knock marks than its something besides the sway bar. You can always get some rubber matting and wrap around sway bar, zip tie in place and go over some bumps you know cause the issue.
I assume ya havnt replaced all the rubber parts in the subframe (looks like a pain in the ...). Could be one of those hard to see unions that is the problem.
. As I am into performance I changed all the suspension front and back to H&R Springs with Bilstien B8, s.. I changed both upper rear shock mounts(Bilstein mounts) New upper spring mounts , sway bar end links and couple of the control arms..
May I ask, what P/N is agenuine Bilstein( not Febi Bisltein or Sachs ) rear upper shock mount you bought ?
This is a rear upper shock mount. Ignore the garbage Lemforder brand.
This is it.. (picture) I know it says E63 but it's the same for E350... Took me days to find this as they are not listed anywhere for E350 with non air sport suspension.. Way I found this is if you go to Mercedes dealer sights they show the shock mount part # in the image for the rear Sachs shock but you can not by just the mount.. But if you cross reference the mount part number it comes up as mounts for different models but not for E350... Weird but it's the exact same mount.. I have searched everywhere but nowhere can I find mount listed as E350
This is it.. (picture) I know it says E63 but it's the same for E350... Took me days to find this as they are not listed anywhere for E350 with non air sport suspension.. Way I found this is if you go to Mercedes dealer sights they show the shock mount part # in the image for the rear Sachs shock but you can not by just the mount.. But if you cross reference the mount part number it comes up as mounts for different models but not for E350... Weird but it's the exact same mount.. I have searched everywhere but nowhere can I find mount listed as E350
May I ask, what P/N is agenuine Bilstein( not Febi Bisltein or Sachs ) rear upper shock mount you bought ?
This is a rear upper shock mount. Ignore the garbage Lemforder brand.
Thank you.
How bad were the lems? I ordered the bilstein shocks from fcpeuro but didnt realize the mounts were lems and not bilsteins. If they are real bad Ill order the ones from rock auto and go from there. Thanks
The short answer is, Lemforder or Sachs ( same ZF group ) machining for the resting surface/area of the C clip of the damper, is so bad, it will damage the C clip and the damper piston too.
I read that post a couple weeks ago.. As that is not cause of my problem I did fix the problem with the counter bore on the mount.. I have been a CNC machinist for over 30 years.. I just bored out the counter bore on the mount . .02 deeper and made a stainless steel insert to use instead of the ring that came with my Bilsteins.. Problem solved.. But I am still looking for the knock I'm getting.. Sounds exactly like the shock is hitting the underside of car.. Driving me crazy cause I still can't find the source..
I read that post a couple weeks ago.. As that is not cause of my problem I did fix the problem with the counter bore on the mount.. I have been a CNC machinist for over 30 years.. I just bored out the counter bore on the mount . .02 deeper and made a stainless steel insert to use instead of the ring that came with my Bilsteins.. Problem solved.. But I am still looking for the knock I'm getting.. Sounds exactly like the shock is hitting the underside of car.. Driving me crazy cause I still can't find the source..
I want to have you as my neighbor
Yes, I too will do that when the time comes, since I got now 5 of dumb-azz Lemforder rear damper top mount....LOL
Can you record the kind of sound you are getting from rear suspension/arms system ?
Hard to record cause it only happens on a series of bumps in a row or a drop off such as a pot hole . But it's exactly what a shock would sound like bouncing up and hitting underside of car.. Strange is if I tighten the torsiann bar the noise goes away for a bit and then gradually starts again. But it's not the torsian bar doing it . If had the rear suspension apart multiple times with no luck..
By the way how do you like the B6s.. I have a full set of B6 and Koni red in my garage both sets have under 500miles on them but I don't know anyone with a W212.. There just collecting dust
10-04-2023, 12:13 PM
