Sharing.......

As car is aging, I am on a shopping list.

Looking at the EPC for my flex disc : Supposed MSRP is U$480 each.






The manufacturer is SGF, but you can't ever buy direct from them.


Above is flex disc still on the DIFF. Aug 2023.


Mine is still ok, but rubber is rubber. It will age. July 2025 inspection.

Above is flex disc ON the propeller shaft.


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240 411 01 15 is the physical P/N stamped on the unit
000 411 15 00 is what EPC number it as.

For reason unknown, EPC often has its own P/N which is not the same as the stamping on the product.

If A240 411 01 15 is being searched using EPC, it will be for a few models, including W222 AMG S63
on the other hand, W221 is also using 240 411 01 05 : https://www.ebay.com/itm/33624617393...3ABFBMpMCP_NNm


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I dont understand the amount of price rip-off MB is doing for flex disc.
US$100 retail at the most...... becomes MSRP US$480. 200% is OK, but 500% is king of throat slaying.

I read on other MB forum, Febi Bilstein buy from SGF and sell it as Febi. So we can get lucky getting SGF unit at low cost.
However, I can't find Febi Bilstein for my E400.
I can only get Topran, but from Europe....which many sellers do not ship to Asia.

AutoDoc does not ship to Asia.

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Flex disc is not one size fits all.
It has to match the engine torque/HP and the design of the propeller shaft which some uses 3 fingers ( 6 holes ) and some 4 fingers (mine) which is 8 holes.
Surely the PCD of the holes has to be dead accurate too.

One thing I just realized about W212 drive shaft.
It only has a single universal joint ( cardan joint) , which is okey for low angle tolerance , hence the flex discs are the 2nd "universal joint" which act as phaser.
Google driveshaft phasing ...... when two universal joints are used.








So MB is very strict on how much angle is allowed for propeller shaft.


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If we calculate the total LOW and HIGH of 3 angles, we get tolerance of maximum 1.5 degrees allowed as misalignment.




Surely we want to be zero degree, if possible.


Engine mounts (2) and tranny mount is reponsible for Angle 1.
The middle bearing holder can be shimmed with thin copper plate for Angle 2. There is a WIS on this.
The DIFF has washer of various thickness sold by MB, for Angle 3. There is a WIS on this.

The tool to measure the angle 1 and 3 is expensive and need special adapter to get the true level or zero horizon as per MB supposed "zero".
They use Romess brand , as always.
If mid position of propeller shaft angle, it is easy to read, any good inclinometer can do it,but the problem is we do not have the datum for the supposed "zero" degree.

Due to language and vocabulary limit of mine, what I meant by MB supposed zero is explained below :
Let say center of tranny output flange center is 25cm above earth/floor , and the DIFF input flange center is 23cm, there will be a minor angle down of 2cm at X meters long = 1.15 degree...
that 1.15 degree is the supposed zero datum angle I am refering to....if this makes sense.





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This guy company is the manufacturer of driveline balancing machine, the one Mercedes uses.
I follow his channel, albeit Land/Range rover and not MB. His knowledge is awesome.

Minute 13:05 to 20:10 is so awesome an information of drive line balancing



GLC driveline seems more refined, in terms of angle tolerance.
CV joint label A and the label B I think also a CV joint or a protected universal joint.


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Thank you for this in-depth research of driveline parts.

The flex discs have a hard-life challenged by output torque + exhaust heat + misalignment from both ends + worn U-joint support bearing gently cradled in rubber.


prop-shaft U-Joint bearings...

I wonder when we should refurb the U-joint 4x needle bearings at once or with other refresh parts?

After further thoughts... it's the worn u-joint bearings that works out the support bearing.

I guess the sagging rear springs are in charge of misaligning the rear diff. to strain the U-Joint needles.



made in china AMG

 

Rear spring sagging will not effect the driveline ( propeller shaft ) angle, but it will effect the CV drive shaft angle.
If we read the requirement of the CV driveshaft angle at ride height, it is nearly flat at -0.06 degrees only. This is basically zero degree.

The more straight the CV drive shaft operates, the longer the life will be.

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However, if REAR subframe mounts .....those 4 went bad, it will effect the position of the DIFF and hence the angle of the DIFF input flange.
2 big bushings of the DIFF also will effect DIFF position or angle. The single DIFF front mount is more metal than rubber, but it can go bad too.
I have replaced all the mounts 7 mentioned above.

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Need to remove my entire CAT and exhaust system up to final silencer , for me to simply measure the two pieces drive shaft angle.
At the least if I can measure at this two spots, middle of each propeller shaft, I can reverse calculate if my middle bearing holder need shimming or not. Them two should read same degree of angle.

 

I remember when we first got my wife's W124 Estate circa 200K miles, its flexdisks were toast, afaik they were original. replaced them with the MBZ parts, they were still in great shape 10 years and 80K miles later when we sold it.

 

Yes, this flex disc last a long time, but what we can not measure is its deflection amount when torque applied.
Example a new one say deformed by 3mm at full power, oldie one may deform at 5mm at full power.

On yachts we use flex disc too, single unit only, not all , some British yachts like to use them. Example Princess Yachts.



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Flexible coupling does not remove the needs for proper alignment.

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2010 C200 W204 at approx 73,00KM in May 2024
Tranny output flange side

Very very minor cracking is visible.


Again the P/N at EPC is being "cloaked".


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3 fingers = 6 bolt holes, not 8 like mine.



If I search in EPC for A210 411 04 15 as per stamping on the rubber, it is being used on W222 and W205.


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Weird, I use my 2018 EPC number for the W204 flex disc : A000 411 00 00, and the newest EPC ( USA dealer ) in fact is showing the same A210 411 04 15 stamped number on the rubber as latest P/N.
Its cheap ....damn.


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Dang, confusing this P/N cloaking
I mean I dont want to pay US$350 x 2 pcs for sure !!!!!!

 

This is what others been saying about Febi is using SGF brand, which is what MB is using.
Supposedly this is for the W204 C200