S-Prihadi

Gents,

Some sharing.
I nearly add 1 more screw-up job to my collection

I removed my Electric Power Steering complete assy, so that I can survey hand/tool access for my big job year 10th to 12th program,
this one : https://mbworld.org/forums/e-class-w...rts-renew.html


Here I forgot VITAL POINTS to note :

01. Make a label and paste it on the steering wheel .....to remind yourself that the steering system is disconnected at the EPS rack and pinion


02. I doubt DIY have a steering wheel locker like an alignment shop.
Get a string and tied down yours steering wheel to the brake pedal. Cheap simple method to make spinning of steering wheel by more than 20 degrees .... then IMPOSSIBLE aka SAFE.


03. Why 01 and 02 need to be done ?
If we forget that the steering wheel is not connected to the the steering rack and then spin the steering wheel more than 720 degrees, the ribbon cable inside the clock spring will be torn !!!
Like this video below , unlucky guy


I feel you man.


.
WHEN AND IF YOU REMOVE YOUR STEERING COLUMN.
Do not play with the clock-spring center position. It has a red lock where unless you press it, the clock-spring wont spin...as safety.
The center position of this clock-spring is actually at the magnetic sensor ZERO degree, and you can't see it unless using scanner/xentry when and if the steering column
is already installed.




Mark your steering shaft center position towards your steering wheel, using marker. Because you may get confused as the MB made 2 markings similar per 180 degrees apart.
On my car the double lines marker are what I need to use, not the single line marker. A1 double line at steering shaft and A2 the wider slot at steering wheel.



.
MB WIS video may show you this version below which is so different than mine. So do not trust the video and see what is your version of marking, before you remove the steering wheel.



.
MB WIS document may show you different too





.



.
I marked red, not too visible in the photo. Let me zoom.




My screw-up no 1.
AA. I did not place a label DO NOT TURN STEERING WHEEL.
BB. I accidentally turn the steering wheel like 360 degrees, because I wanted to re-install the steering tie rod and need some angle to work my torque wrench ...
and then I remembered the steering link is disconnected DUGHHHH !!!! There then I remembered the ribbon cable at clock spring could be damaged

I was already imagining this carnage





My screw-up no 2.
I have WIS/EPC but I assumed too much and did not read it when I tried removing the steering wheel column, to verify my clock-spring at steering wheel column is OK or not.
I remembered watching MB video on steering wheel column removal, and the leather cover seems easy to pull out along with steering column, like below :




Leather cover:




So the MB-Workshop video scene is NOT a W212 !!!
A W212 has release clips at the rear end of the steering column and the leather cover stay as-is in the car.... LOL.




.
And the plastic used by MB must be re-cycled one. Bad bad quality in my tropical climate, albeit my car is always garaged never under the sun.
The leather cover plastic part on mine is already brittle at 10th year and it cracked like below simply by me applying simple force.





The clock-spring actually can do full 360 degrees x 6 rotations if from LEFT to RIGHT.
So one would imagine that the middle one would be 360 x 3 rotations, but it is not, mine was 180 degrees off when I tried using that simple method.
It all depends on when the steering column sensor was assembled, where did the person zero the steering angle sensor at.

Imagine the gold color disc is a camshaft or crankshaft tone wheel. That disc and its reader placement is where the ZERO will be.




=====================


The moment the tie rod ends are placed back and tightened, I must do wheel alignment as 0.3 degree out/off is easy and my
steering toe value itself is only 9 minutes. So 0.3 degree is 18 minutes and that is a lot of error. 1 degree has 60 minutes.




.


.



.



.

If I push harder to the right, I can get extra 5-7 degrees.


.



.

I push harder to maximum left. Hence higher degree.


One tip.
When I first installed the steering wheel, there then I realized the angle sensor was not is its ZERO position.
Still, I played with the steering wheel and then the ERROR came.
I guess +180 degrees to one side exceeded the allowed limit.
But what I do not like is, steering column module N80 declared the angle sensor as DEFECTIVE and not over-range.
The ERROR does not reset itself when I "centered" the steering to angle sensor ZERO. The DTC has to be erased.
So here one must never swallow raw, the DTC description.
Just like say engine sensor/s connector being disconnected, often the DTC is DEFECTIVE sensor and not Open Circuit.


The W212 when I need to replace the leather steering void cover, I need to un-do the HVAC vent from passenger side and then proceed to driver side and remove instrument cluster plastic face and only
then I can remove the leather steering void cover. I hate interior works. My fingers are are not delicate !!!!




.
Will continue a bit more after this..............

S-Prihadi

Some related WIS, attached.


Tips. The red dot alignment indicator at 6 o'clock position of steering column N80 as per WIS.



.




=============


Safety lock, one time use, will be broken ( on purpose ) when you remove the connector of N80. We can buy this. Small 1 cm wide.
The black one is mine, already broken. New one orange, see the NOT broken part....



.




Over n Out

CaliBenzDriver

Thank you Surya for your discovery tour of steering. The Steering Column host many functions all connected to the SCModule for networking.


THE SCM sandwich stack
This can ve removed as one unit to get worked on away from the car.


marginal connections from missing solder
(this particular sample unit not from a W212 facelift).

Once soldered the SCM noticeably work with electric steering rack to holds 0° center at highway speed... car becomes nice to drive not wandering around unstable.

As mentioned some of the plastic surround vinyl fabric is extra fragile... this helps witness any work done in the area

ChuangTzu

I don't know how you have the time to do all this stuff, much less document it in such great detail.

Thanks once again. Though, I hope I never need this. I, too, hate interior work.

S-Prihadi

I hate this fragile unit Cali, more so when ribbon cable is involved.
I fear the plastics get broken again , but this time at the N80 plastic body itself, the inside of it where I would need to do X Y Z for re-soldering.
I will skip re-soldering this one until sometime later, good thing it is easy to remove N80 from steering shaft ....now that I know the 101.

You know, when I first removed the air bag on steering wheel to replace the N135 switch board for my tranny manual UP-DOWN, we need to push the lock spring inside it at an angle.
I slipped and tear the also fragile foamy material of steering wheel....
Back then I could not find the video of what I am actually pushing, until I managed to remove the air-bag of course.



I was feeling the target, I slipped and went above and over the target and by push tool went side ways and and tear that foamy material.



.



I then realized why this foamy material is made on purpose this fragile.
It has to explode/tear along during air bag gas release you see, hence it is made from such MUST-BREAK material.


So i use my usual magic tape ( nano tape ) whatever they call it, this one :




THE BIG TEAR ABOVE AND BELOW. Left side of steering. My left hand accuracy is low. I am a total right hander.



Right side tear, not as bad as left side. No need Nano tape.



I hate interior !!!!

==============


The warning I will be placing when I remove my EPS steering assy again.

S-Prihadi

Me 98% retired , and I got itchy hands....

S-Prihadi

UPDATE :

So, those with Electric Power Steering, EPS itself has its own angle sensor. That means you/me deal with 2 STEERING angle sensors.
N30/4 ESP stability computer seems to use N68 EPS's angle sensor and not N80 steering column angle sensor. I purposely made 0.9 degree difference between the two.
I am sure EPS angle sensor is more direct, as it is the steering system direct to the tires.



.

Better if Xentry write : STEERING RACK ANGLE, not Steering Wheel Angle.



Steering wheel to EPS has a few interconnection which are links with yokes and a rubber pad.... which can produce minor angle "drift" or play.




ADD : 1 more yoke set damn. Source : https://www.ebay.co.uk/p/20024361179


Oh oh.....I hope the rubber damper has metal insert in it, if 100% rubber only .......when this rubber aged and crack while we are driving hard...how ???






I can make N80 and N68 angle identical, but need to tap the steering so very soft. Those "play" causing items above is why the angle data can be NOT 100% similar...close but has a bit of play still.

Learning everday................

S-Prihadi

Shi-et, MB does not sell this rubber coupler stand alone.
This damn thing can make steering free-play, like a JUNK car !!!...before it can break.





For W124 you can buy stand alone the rubber coupler/damper only





BMW E46 M3 ( 2000 - 2006 ), seems there is like some sort of cord. Like tires ply. Can buy stand alone this damper/coupler, nice.


The utube



ADD: It seems it has cords inside as safety. Must be German thingy..... Porsche 928, the 80s era.






Hhhmmm..... more mechanical stuff to worry. I am keeping my car to its 20th bday, that is the plan for now.
Worry on how to modify or custom made it when it get loose/weak and have free-play....and I can't buy it stand alone Dugghhh !!!

juanmor40

@S-Prihadi , I am sure you can improvise a new WTF steering coupler. It is just a "flex disc" with a central and 4 holes around.

By any chance, does the W212 uses the mechanism shown in the video

S-Prihadi

No, mine is simple classic double yoke. Must be on all W212 too, as per EPC.





I probably can ask local PU bushing maker to mold one for me in the future, copy the rubber shape and hole MB uses.
Uses bolts and nuts , no more rivet. Need to take out the whole adjustable steering thingy

S-Prihadi

Okey dokey, new leather cover arrived with a new orange color connector safety lock.

HVAC vents and instrument cluster hood removal is here : https://mbworld.org/forums/e-class-w...er-region.html

.
To be sure no explosion of airbag.......... I made another note :







.



.




.
Better visibility for arrows



.



.




DONE




.

S-Prihadi

I took my car out for a drive today.
My steering wheel as expected will be no more zero straight...... is now about +7 degrees to the right as STRAIGHT ahead.

Will do alignment this week.

Amazing, a mere 1 millimeter difference in how the two tie rod ends were re-installed by me compared to factory installed in 2014, the zero-straight-ahead has shifted.
I used this calculator : https://robrobinette.com/ConvertToeDegreesToInches.htm

If I, during re-installation of the ball joints created extra 1 millimeter ( 0.039 inch ) distance, it will result in a difference of 0.1 degree of toe-in.
My front toe-in total value is only 9 arc-minutes or 0.15 degrees.
1 degree = 60 arc-minutes.

CaliBenzDriver

MS, it is weird your steering has shifted 7degrees... I have removed my whole steering column without any difference besides SCM improvements.

7° sounds like one-teeth difference... but the steering couplers are properly splinned, right.
So I don't see how they can be inserted wrong... perhaps it is possible afterall ???

​​​​​​

S-Prihadi

.
Steering wheel to spline has proper alignment marks and is properly aligned, or else safety red dot will not sink in.

.


.
Spline of steering system to steering rack assy has the green alignment plastic, it can't go in wrong.


.




You are lucky your ball joint was tightened back to its home position exactly.

I probably for 1st ball joint installation , it was not 90 degrees perpendicular or not super straight facing the sky , so the steering knuckle is then actually have to re-position itself.
The 2nd ball joint and steering knuckle automatically has to follow too, whatever offset I created at 1st ball joint.

Perhaps what I needed to do was to let loose both ball joints and slowly tighten bit by bit both ball joints like how HPFP fuel pump 2 bolts are done small 90 degrees increment
per bolt alternatively ....to equal the load or to go in super straight.

Anyhow WIS always request alignment after removing steering rack assy.
Lesson learnt....

CaliBenzDriver

MS, so you're saying the steering column did not introduce 7° but then it's the rack mounts or tie rods, right?

Do you know where our ELECTRIC RACK GND while we are in the steering department ??

We drive in salty ocean air so I'm thinking our rack needs a good GND that we should learn to service regularly.

S-Prihadi

Yes, my ball joints installation produced that slight error, not other mechanical or electrical.
What happen is my steering wheel physically need to be +7 degree to the right to get a true straight. It may be only +5 degrees or so, but its an estimation.
You know some roads have angle/crown whatever they call it and keeping straight need minor compensation, but this one I am sure mine is off center already.

I recalled when playing with correction bolt for the front suspension arms , the approx 3mm shift of bushing center hole position will cause my steering to go like 20 degrees off center.
Suspension system is so sensitive to any minute changes. Even firmer new bushing can create different alignment values, like my rear suspension system is now getting closer
to factory spec PERFECT camber after 3 bushings replacement and the camber arm. However I did not sit the rear left spring a 100% to its end stop point and my left rear is
not close to PERFECT. I have done the spring re-seating , but I have not done alignment yet. My plan is this weekend I will do alignment.


Above : See my RIGHT rear camber was at best -1* 46' at 13th alignment, before 3 new bushings and new rear camber arm.
By 14th alignment with 3 new bushings and rear camber arm, I can't ask a better camber of only 1' arc minute off from perfect -1* 27' MB spec.
See my rear toe at 14th alignment the BEFORE one, that went bad from the LEFT side rear spring is not seating well.
Left rear Camber is also not good.

This is what I meant by LEFT rear spring is not seating to its end stop.




Right rear spring, it is at its end point.




.
My right rear camber been the one I worry about ever since I own the car in 2018.
Do note, maximum allowance of camber difference between L and R is only 0.5 degree or 30 arc minutes.




People complaining their rear tires eating its inner side, I don't. It wont ever happen to my car.


===============


My Electric Steering has its own negative wire feed, so it is using isolated ground.
Someday when i happen to be under the car I will unplug its big power connector ( there are 3 connectors ) , and I will ohm the EPS negative power pin to ground,
that is the way to confirm if indeed a 100 % isolated ground.