S-Prihadi

Gents,

Here is an interesting case study.

From MB factory, the 2 control arms of front suspension : Caster and Camber Arm, will get STANDARD BOLT.
If you alignment value for Caster or Camber is out a bit, while the bushings and the ball joint of the arm is still good, you can use CORRECTION BOLT.

Item #1 to #3 are the STANDARD BOLT set, with new type NUT ( #3).


Item #4, #5A , #5B , #6A and #6B are the CORRECTION BOLT set




Item #3 close up. So now it uses thread locker and not the Claw type locker on top of the nut.





The region I marked NOTE 1 , NOTE 2 and FLAT are what you must pay attention to.





These are the holes shape ( 2 holes per arm ) on the front subframe to accept these bolts, be it CORRECTION or STANDARD.


CORRECTION KIT washer will be used when and if correction value is needed. Only Plus or Minus of a minor degree is possible, approx 4mm shift.


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WARNING !!
Since the Left and Right Camber and Caster Arms are opposite in its installation.
ADDING CAMBER means the Arm it self get pushed OUT , outward of the car.
REDUCING CAMBER means the Arm itself get pushed IN to the car, inward.
So below washer position : A as REDUCING and B as ADDING camber only applies for FRONT RIGHT Camber Arm. If for Front LEFT Camber Arm, it will be the opposite.



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Which one is CAMBER and CASTER ARM ?



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Will continue...........

S-Prihadi

So what is the interesting case study I speak of ?

It is about my friend's C200 W204 which uses the same bolt holes with 2 notches set up like our W212 for the Camber/Caster Arm bolt holes at Front SubFrame.
In Nov 2011 I noticed his Caster Arm bushing already torn. Both.


So I told him to go to my Indie and replaced them with a new one.


Fast forward this 2024, few months back in May 2024.
I personally replaced his front CAMBER Arm and found out a dumb-azz mistake MB Indonesia did during assembly of this 2010 car. This car is locally assembled in Indonesia.
MB Indonesia installed a CORRECTION BOLT in lieu of a STANDARD BOLT !!!! For a new car in 2010...Dugggh !!!!


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Good thing I have 2 spares STANDARD BOLT from my own car, which one of the arm already uses CORRECTION BOLT.
New STANDARD BOLT set is a 60 days special order ....WTF !!! So I ordered them, all 4.
At this point in time I did not give much thought.

Come few days ago, after this car has its engine works done yada yada for 2 months due to spare parts delay........ I sent the car for wheel alignment.
I was in for a shock !!! Such screw-up value and I managed to track down this car older alignment file, back in 2022.




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Specific for the whacky REAR Camber value, this I need to dig in deeper. For now I suspect it is from the un-even worn out tires.
The rear toe was not adjusted yet, as the space is too tight for my usual tool for W212 and I need to remove the undershield to access the adjustment bolt...damn, unlike W212.
Will update this one on separate post soon.


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Reading the values, I then recalled that the FRONT Caster Arm was replaced back in 2022.
So I traced my photo archive of Nov 2021 and see if the FRONT Caster Arm also by MB Indonesia mistake, was installed with CORRECTION BOLT or not ?

Yes indeed CORRECTION BOLT too, WTF !!!




So 2 days ago I removed the CASTER ARM bolts ( both ) and learnt the damaged done caused by 2 idiots !!!!


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I said 2 idiots.
First Class idiot is MB Indonesia techy, which if this 1st mistake was not created in 2010, the 2nd mistake wont happen to the 2nd poor idiot.
2nd idiot ( accidental idiot ) is a poor soul who does not understand CORRECTION BOLT, my indie techy.


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Seeing this is why i want to share you all.
01. If ever you bought a used W212 which has CORRECTION BOLTS already installed by previous owner or by accident from MB assembling plant, do observe how to ID a Correction Bolt as I have shown above.

02. This 14mm bolt set is set very tight, 100Nm and 180 degrees, which is easy 300Nm of torque. 300Nm for a DIY without a full height standing workshop lift, but limited say 40-50cm like my Qucik-Jack working room, is a nightmare to work on.

03. You will be tempted to use impact hammer, because you see there is working room for the bolt head, but not the NUT.
You then use impact hammer or decided that you will loosen the bolt set from the BOLT and not the NUT.....here is where a correction bolt cut-out will strip the notch of the subframe bolt hole !!!
Never never loosen a CORRECTION BOLT from the bolt, it has to be from the NUT as the BOLT need to stay put/still, because 10 degree movement of bolt is already enough to tear the locking notch
at subframe bolt hole.




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STANDARD BOLT will automatically center itself, unlike CORRECTION BOLT.




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Another caution when using Correction Bolt Set, the special locking washer.
This washer must never be allowed spin out of its place during tightening. Otherwise it will not work as intended and it will damage the subframe bolt hole region like below.

Pink #2, Twice imprint of locking washer, this means first one by MB Indonesia techy and 2nd one by my indie techy
Double Uncle Murphy !!!!


Single imprint, pink #2




So, becareful guys.....................