Sharing..............


I had minor impact to my left front suspension + steering system, reported here : https://mbworld.org/forums/e-class-w...wide-road.html

From that trip completion, I used my car a little bit.
Yesterday Sunday I went to replace my front right bent wheel and roadforce balanced it.
Bent wheel post is here : https://mbworld.org/forums/e-class-w...-5-review.html

The wheel shop is a bit far ( newest roadforce balancer machine in town ), thus I am able to do a bit more distance which includes long straight paid highways and
I am seeing my steering is not 100% centered anymore in order to achieve a straight line drive. Steering wheel has to be a bit "left" physically. Tiny bit to the left.

So I measured my front wheel toe today, the simple way.

First I set my Electric Power Steering to zero degrees and my steering wheel ( N80 SCM ) to zero degrees too, to confirm that steering wheel is indeed zero degrees in respect to EPS.


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I use a 100cm long ruler with water level for flat horizon, placed it at the middle of the wheel/rim. Blue tape is the middle of the wheel/rim.




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The result :






While my front spoiler/bumper is not a super rigid structure like older car tough bumper system, it is still use-able as reference point.
I am going for alignment check tomorrow. I think the left wheel TOE-IN is now too much.


There is no impact marks on left side steering or suspension system.
Will update.........

 

Your car is obviously defective, even the steering wheel was installed on the wrong side, LOL. it looks like an alignment is in order from your tape measure check, that's quite a difference.

 

This is a great topic because yesterday evening I drove over road construction plates downtown about 35mph and this morning my front suspension developed a bit of extra vibration arounf 60mph.
I had similar experience 6 Month ago with uneven construction pavement. 2 or 3 inch step screwed up my chassis with vibrations. Rotating wheels Front>Rear plus new tires did notably nothing at all to help.

> In Question... :

• wheel bearings (flat roller?)
• Front sway bar bushings
• Inner/outer tie rods ball joints
• camber control arm

> Not so much...

• rotated F/R wheel/ new tires
• caster control arms
• strut mount
• Camber BJoint

Yet steering remains super precise, so I can't think loose tie rods are involved here. Vibration is more in the wheel suspension than steering alone.

Long story short I don't know what feature MB developed to create this weakness.

 

The Front TOE is out of whack........ on the left front wheel, as expected.
But I never expected to see my rear RIGHT camber grown from OK to BAD....
I have to jack up my car again and take a look at the rear RIGHT. I paid close attention only to Rear Left from the impact.
Rear Right or/and front right was never the one getting the impact.

See 15th to today's 16th alignment result.



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I do not recall getting my rear right wheel or suspension whacked in anyway.

The rear suspension very recently, 4,000KM ago has new bushings for spring control arm both ends , where one is a unique ball-joint like bushing at wheel carrier/knuckle.
A new bushing for thrust arm #540, at wheel carrier/knuckle.
A new camber arm too.
All above items are very related to camber.
All documented here : https://mbworld.org/forums/e-class-w...hing-tool.html

The rear right camber degrading was obvious actually since the new parts replaced as per above link. Very odd.



Very weird, the Right Rear camber creeping by 34' minutes in 4,000KM is not right. 34' minutes is 34/60 or 0.56 degree.



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I think , next I must replace the #540 thrust arm/pushing rod. This one is do-able without needing to remove sub-frame from the car.
Only #350 Strut Rod / Radius Rod and rear sway bar will need subframe to be removed from the car if they need replacing.

I must also re-inspect the new unique ball joint like bushing #40.







The unique #40 bushing behaving like ball joint.


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Damn.... more work.

 

@S-Prihadi I know one thing…if I had any association with a race car team, I would hire you immediately. Your attention to detail and specifications is quite impressive. Thank you sir

 

I done some calculation.

If my camber has say drifted by 30' minutes or 0.5 degree, below calculator pointed out that distance moved is 2.54mm or 0.1"



So the Left rear wheel carrier could be pushed out at its bottom or at the unique bushing by 2.54mm OUTWARD, or the top of the wheel carrier get pushed INWARD by 2.54mm.
Or simply some arms bushings could have collapsed by 1.27mm at the bottom and 1.27mm at the top.... LOL.
Damn, 2.54mm is not easy to find, let alone 1.27mm ( 0.05 inch ) if at two locations.

Come to think of it, maximum allowance by MB spec is +-30' minutes or 0.5 degree for camber below or above target.
Above/below this value, it is end of service life for the related suspension arms & bushings.
So little allowance this 2.54mm or 0.1 inch is.


This is my rear camber full history, after I completed doing front Camber arm correction bolts, for both front Camber Arms, which got abused at the track within 20 laps only.
1 lap is 4.12 KM, so only max 83KM or 52 miles distance and the front suspension system took a big beating.



At 12th alignment, I had to use my OE AMG-Ronald wheel because I damaged my BBS CH-R front left wheel and ordering it from Germany, 2 pcs for spare needed so many months, 6+ months.
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I wonder if my 4 rear sub-frame bushings deformed by X millimeters and they get un-even between Left and Right, to what effect will that have on my rear Camber ?
I guess I might as well replace them 4 bushings and the 3 of the Differential mounts, which all these I already have purchased and plan to do it by year 11th or 12th, or 2025 - 2026.
The #350 strut rod best be replaced too while sub-frame is removed, while doing sub-frame bushings.
The rear sway bar / anti-roll bar will also need to be replaced while I am in there. After-all its bushings are rubber too and must buy complete assy.

Hhhhmmm....more and more work.

 

Glad the information can be useful to other members


If you are good at MATH & trigonometry, which I am not....here is a good read on MB 5 link suspension design. PDF Attached.

 

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Inspection done.

At the moment the suspect is the top rubber shim of rear right spring, item #90.
NOTE : EPC is wrong on the position, item #100 is at the top and item #90 is inside/below item #100.

The spring end did not hit the maximum stop at #90 end stop cavity, there is a gap approx 10mm.





Item #100



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The gap of spring end to maximum end stop of rubber shim #90...... stay the same, be it suspension at full droop or at ride height.
RIGHT REAR



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RIGHT REAR




Suspension at ride height.



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ABOVE is a wheel spacer I bought as an assist tool. When doing rear arms, one has to fight the 5 arms tension when installing the bolts and its a nightmare if we can not get a good hold on the wheel carrier/bearing assy.
The spacer can help as a place to secure my wrenches as my hand power extender and my hands do not get hit by the brake caliper



LEFT REAR - SPRING GAP to #90 rubber shim END STOP. Very small, its almost maxed out as it should.
Damn, I need to fix this too. So my last job while doing bushings was not good enough




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Case study of LEFT REAR spring, when its bottom part also has a gap to its steel shim end stop, Camber value changes.





There should not be any gap between spring end to the steel shim end stop..... at ride height or at suspension maximum droop.


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Rear Left CAMBER value between having a gap at the spring bottom and no gap.
See below, 14th to 15th alignment report. Up to 19' minutes or 0.31 degree change.






I hate doing rear spring, I do not have the proper spring compressor , which should be like this set :





This is inner spring compressor, and not the usual outer spring compressor.


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It seems W211 rear spring compressor tool is different to W212
I am using WIS of W211 vs W212 to see the special tool P/N


It seems W211 tool, the spring clamping plate its the same for W212.
But the tensioning device is not the same.?? Maybe slimmer design if for W212 due to the spring arm access hole ??

The tensionsing device must enter thru this hole



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But I plan to buy this one anyway, I will take my chance : Compatible up to W211 only, by spec.
https://www.pelicanparts.com/More_In...L-007776SCH01B


I respect ( fear is a better word ) MB rear spring, for the energy it contained even in suspension max droop aka spring in only pre-tensioned mode.
The spring arm is also angled. Thus using jack to push up spring arm if spring is not compressed first, is also very very troublesome and NOT SAFE.







.I exaggerate a bit below




Will update...........

 

This is as far as the steel spring end will go towards the rubber shim #90 end stop. It is almost touching.





The two spring shim, #90 rubber (top ) and #120 metal ( bottom ) , they both sit at an angle.









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My bottom steel shim #120 is already kinda worn out. I hope MB Indonesia has stock on hand.






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The steel shim #120 stays locked in place by the spring arm cavity shape.


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The rust on the spring before sanding. Dec 2023 archive..



The same spring sanded today. I will repaint it.




The rust is caused by friction region between spring and the steel shim #120 , when the spring is in use/action, an inevitable process.




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A new bottom steel shim #120 would look like this :




Mine . I wonder what is that extra thingy I marked green......for ?
The red damaged zone must be from spring compression... The spring did not sit well ?



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Mine




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Here is what I am still trying to figure out.

We know the bottom of the coil spring is surely locked in place and can't move anymore when it touches the end stop of metal shim #120, where this #120 shim is locked by the spring arm cavity.
I am wondering, how does rubber shim #90 can lock itself to its holder #100 ?

There is no lock of any sort on #100 shim holder, only rubber to plastic friction. #100 is 100% plastic.




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Side note :

I seen traces of cavity preservation wax ( Cavity Wax A 000 986 72 70 05 ) both on #100 shim holder and #90 rubber shim.
That dried wax is actually high friction and not slippery like silicone grease.




#90 rubber shim has lots of cavity wax inside this channel, I wonder what does this channel does ? Its about 230 ish degrees circular, not a full 360 degrees.



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I looked at MB cavity wax, there was a TSB where a sub-frame of MY 2023-2024 EQE Sedan (295 platform) did not properly get the cavity wax.
https://static.nhtsa.gov/odi/tsbs/20...58920-9999.pdf


I think we need special spray gun to spray this MB cavity wax. This bottle does not seems to have spray head.



3M cavity wax, in a can with propellant for spraying the wax

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I am thinking of this preservative cavity wax, when I remove my rear subframe. I want to be able to inject this wax if possible for corrosion protection.

 

My bottom shim #120 oval-ized already



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MB Indonesia stated 14-30 days, OK, no choice. I ordered two from them,.

I also ordered 2 more thru Ebay.
Dang these sellers only have each 1 unit in stock

So let see which three purchases will arrive fastest.

 

I can't wait too long for the steel shims, which soonest would be 2 weeks if I am lucky, so I "buttoned up" my car.

This is as good as it gets ( spring under car normal ride height compression ) spring end stop for top side rubber shim end stop.

Spring under compression, car ride height. Approx 430kg / 944 lbs corner weight for the rear without driver.




Spring not yet under ride height compression.




The bottom steel shim sits well but its is obvious it is rather deformed if seen from the bottom spring arm hole.





RIGHT REAR - the one with deformed steel shim


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RIGHT REAR - the one with deformed steel shim




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Left rear, shim seems ok.




Left rear, shim seems ok.




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Side by side




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I really hate re-installing rear spring.
This time I do not use at all my usual "outside" spring compressor, 1 unit.
I use jacks only, I use 2 to be safe.


This angle is what I hate. If the spring is compressed using proper MB type compressor, I only need to fight the bushings to get the spring arm angled well.
If the spring is not compressed, I then have to fight the spring too, when trying to get the spring arm ends ( the fork ) to sit well at sub-frame bushing .
It can be done but very crude way, not smooth bolt insertion... but by brute force. I hate it.


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Will update when I have more progress.......
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I got itchy, and went to the alignment shop again.



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Amazing how rear suspension effects so much the front suspension, the TOE.

My front Left and Right TOE went out of spec again because of the Rear Right spring arm loosening and rear spring shim re-seated.
Front Left toe from + 4' minutes went to +13' minutes , so its 9' minutes change and Front Right toe from +5' minutes to -4' minutes, also the same 9' minutes change.



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The rear camber is now even more negative at -2* 05' from -2* 00, because the Rear Right spring has seated better and the ride height is now lower a bit. Duggh.










I measured the rear ride height to the best of my ability, and indeed, Right Rear is 1.2mm lower than Left Rear.
The fronts are both the same.

I wish the alignment machine has Romess inclinometer , it should read this height difference as angle and I can compare it to MB Romess spec.


1st try




2nd try same method as 1st try, so no need to show.


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3rd try, different method.
Find centerline reference with plumb bob, and make marking on wheel and fender lip.



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I think the sealant at the fender can effect reading




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So , I will be replacing the top side rubber shims too and both rear springs, before anything else , like other suspension arms.
The springs is probably now rather "tired" and is sagging down so very very slightly.
The rear springs when with 2 passengers and some luggage , at high speed and bad road to bridge joint, I have at least twice max out the suspension till its bump stop.

I will use the same spring type, not lowered or aftermarket, just genuine MB ones for the comfort and good performance it has provided me.
A2123240404 , 1 red and 1 green dot.

The spring is cheap, in USA is only US$114.30 each.
https://www.mbpartsexpress.com/oem-p...ing-2123240404


Anyhow, the W212 rear spring breaking is not new news. Albeit most likely others got their spring broken partly from accelerated aging from corrosion perhaps....
this spring-y metal will have to hit its fatigue life nevertheless. My roads are bad anyway.


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Its amazing to how a few millimeters matters.
4 different thickness of the top rubber shim for W212.059 with M276.9 engine and various suspension code . Mine is the 13mm, the 3 dots one. We can see the dots on the rubber shim.
EPC called it Stud Count, I call it Dot






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If MB Indonesia has this alignment machine below, complete with Romess inlclinometer and relatively new or minimum super well maintained, I want to try :


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Will update in a few weeks....if not early next year.

 

Those new springs are going to wear in and you will be back in a month, mine are already lower by 7/16" at five weeks from install, my car was aligned just 3 months ago, but my Indy said wait until it settles to align it,

 

Thanks Pierre, I would take note of the new spring settling down time.
7/16" is 11.11 mm , wow, that is a lot.

Do you have copy of the 3 months ago and the one before it, them alignment results ?
I would love to see it for learning sake.
I hope it has Romess value too.

Your spring/s was/were broken or simply tired ?

 

I broke my rusty springs on the way home from Arizona on a raised bridge abutment, I didn't see it and hit it at 90+ MPH with a fully loaded trunk and gas tank, we actually heard them crack! I then had to move some suitcases from the trunk to the back seat for the rest of the ride home. I stopped at the next exit to look under the car, it was obviously down, there was one finger width from tire to fender, but I couldn't see a crack. It was in the last ring before the bottom retention plate. We had just gone through St. Louis and had another 700 miles to go, so I ordered them from FCP Euro and had them changed when I got home, the new springs were really high on installation, four fingers from tire to fender, by the following weekend they were down to three fingers and now a little lower,also the right rear was about a quarter inch higher, so I double checked the mounting plates as you did, but they were correctly seated, car evened out over three weeks and is the same on both sides,three tight fingers, I know you hate the measuring tools, but that's all I had on the road,LOL. I will measure height and report back, but car has definitely settled one whole pinky finger. I'll look for the alignment papers, I had it done before the trip with the transmission fluid, both differentials and the tires road force balanced, that's when I found the bent rim and went to the rim straightener guy.

 

Wow....good thing you and family all OK....

How was the azz of the car when the spring broke ? Was the azz wild upon tire touch down after the jump ?

I like your pinky finger measuring tool

 

Yes, I immediately slowed down, then pulled over to check at the first exit, Since I broke them both, I didn't have a pull to either side, but the back felt very loose, enough that i transferred the luggage, at the moment iit happened, my wife said "oh, that wasn't good" LOL. But we made it home, driving slower and carefully, I knew that if I had to find a Benz dealer and have them changed out it would have cost a fortune, as it was I got them from FCP for 140.00 dollars. I will get a tape measurement when the car gets home, but when they first went in, the rear was the same height as my 585 code luxury,but that's the factory springs after 13 years and 30k miles, it has since settled down considerably and looks more like the 677 code sport that it is...