S-Prihadi

Hi Guys,

Monday I will call their local rep office to get to the bottom of this nonsense. Buy direct from them the same item, and re-inspect the product.
This way I can eliminate a possible original packaging but a fake product inside it.
I doubt though I got a fake product, as ZF Aftermarket themselves have a local presence in Indonesia and the product itself does not look crappy..... hhhmm, until I go into its deep details compared to MB original one.
https://www.zf.com/site/locations/en...html#undefined

ZF owns Lemforder & Sachs, among others. I know ZF products very well, for their marine transmission and special high speed surface piercing drive.


On April 2021, I was doing routine maintenance :
https://mbworld.org/forums/e-class-w...nspection.html

So I replaced the rear damper mount (2) with Lemforder. Testing sake and also because I have approx 1mm more compressed mount on the MB original back then April 2021.




Yesterday-s, Thursday to Friday I was messing around with new rear damper set, the Bilstein B6. I found my Bilstein B4 at certain "wavy" road with highs peed corner, a bit too soft...the rear ones only, front is OK.
Bilstein B4 afterall is very close to OE spec,but handles much better than the SACHS which is the OE for my W212.

So, yesterday I removed the Bilstein B4 rear dampers which the Lemforder top mounts have served only at best 2,000KM-ish.
First it was the Right Side Bilstein B4 damper and I saw the clip got bent and it kinda "eat" into the groove it is parked at, which is the piston shaft of the damper.



So I thought, DAMN !! Where did I screwed up back in April 2021 ?
I know I aligned the clip well into the cavity at the top mount and all correctly torqued.

Fine. Lets see 2nd damper, left side one removed and inspected. DAMN x 2 .... Same problem !!! Clip bent too and piston shaft also minor damage. Hello .... what happened ?




So I took close up photos to see what is wrong with these Lemforder ????
Oops, 1st alarm bell. How the hell the bore hole can be 0.06mm bigger on the Lemforder ?



Bottom side, where the steel clip cavity is at the top mount.
2nd alarm bell......To me it looks like the cavity is not pure square, its kinda a bit chamfered... ??




On the Lemforder : I don't know if those rough finishes are part of the rubber curing process or what ?


3rd alarm bell. Oh oh... un-even pressure marks showed the clip cant sit well on the Lemforder clip's cavity.




What kind of metal surface finishing or alloy is this Lemforder ? TOP SIDE of the Top Mount. This is where the nylon nut resides. Without zooming the photo, my bare eyes can't detect the differences.





This is bottom view.




A new damper, Bilstein B6





Original SACHS is below , which I replaced with Bilstein B4 on Oct 2019 at approx 20,000KM. Today car is 32,000KM max.
This clip of SACHS can not be removed. The Bilstein one, B4 or B6, we can slowly spin the clip out.



Kept in my cousin's garage and must be rain soaked... much rust hahahah. SACHS original to the car.




I don't know why, but MB does not want to sell rear top mount only..bloody hell. I can't also buy the bump stop bushing too.




I traced the 204 part number...........damn, even with Class 204 which is the same top mount, NO MORE AVAILABLE ...






I think safest bet is to buy SACHS one, assuming since the damper is made by SACHS, the top mount should be SACHS too , the original manufacturer.




Bilstein B6 installed. Using back the old MB original top mount.




Bilstein B6. Year of manufacture Sept 2018. Not too bad. I got my front Bilstein B4 from USA in 2019 and got a 2016 unit ... LOL



My DIY wheel stands set (4 pcs) is so important for me. Without it I can not do proper tighten/torqued my suspension at normal ride height while being able to be under the car with enough working space.
I am very glad I have them.


Piston push-in* pressure, in KG : ( *the amount of force I push dow to get piston to start sinking slow and constant when compressed )
SACHS original at 24kg. Measured today at age of approx 20,000KM.
Bilstein B4 at 22kg. Measured since 2019 as new and also few days back ( 12,000KM old ) , same 22kg.
Bilstein B6 at 34kg. Brand new.
Accuracy, approx 2 kg. Weight of the damper 1.5kg ish.

Above value is for reference if anyone wants to relate "firmness" of a damper based on slow push.
Remember, damper is a speed device, meaning the faster you pressed it down, the more resistance ( kg force ) required. It will depend on the high speed valvings inside it.
This is why Bilstein B4 even though at slow speed push is 2kg less than SACHS, at high speed corner its more compliant.
I do not know what are the actual dyno-ded value of these dampers.
https://suspensionsecrets.co.uk/damp...phs-explained/


Short test last nite showed on bad roads, the B6 does feel a bit more firm.
On the wavy corner I speak of, I can't test fast enough yet as it was Friday nite 10pm only and traffic is still crowded.
There is a also a section of straight elevated highway, but because of different ground elevation and poor construction + poor joinery, at high speed 170KM+ it is kind of dangerous that road in terms of
"loosing" straight line tracking as the car weight on the tires will change with the wavy road and if a standard suspension used...... its kinda scarry.

When I am done testing these two locations and more bad roads, I will get back to you guys.
It is quite unique now that I have B6 at the rear and B4 at the front.
I never mix dampers this way....

END for now.

S-Prihadi

Crazy ZFAG Aftermarket Jakarta office.
2 days phone call and no one answer the phone.
How would one sell their products when I can even contact them ?

I wrote to ZF Europe via its website : https://aftermarket.zf.com/go/en/lem...r/contact-us/#
and fill up necessary info, but too bad limited to only 3 photos upload.
Their automated system is fast, within 3 minutes of my data entry, zfservicedesk@zf.com <zfservicedesk@zf.com> replied.
I hope a human being from ZF Indonesia will contact me soon.

I think it is a blessing that I bought the Bilstein B6 rear damper, because next week I will be running off to Bali again by car.
Near 700KM is by paid highway ( total approx 1,200KM ) and there are some better quality part of this paid-highway system I can do 200+ KM/H for a bit.
Imagine if it weren't for the Bilstein B6 and having to undo the Lemforder top mount, I would not have known of the potential accident
waiting to happen if I go fast and hit a wavy ( bad construction ) part of the highway and the damper piston lost its top mount.

Worse, if while doing a left corner hard and I loose a damper top mount and loose grip so suddenly, I can skid out and get hit by an incoming truck.
If for a right turn, and then I loose grip, I will hit a tree , I will choose a tree anyday vs a head-on with a truck
I am on a Right hand drive car , my country's non-paid highways and supposedly "interstate" road............... it is garbage single lane road 2 way traffic like below :






This wavy elevated highway out of Jakarta is an example of local dangerous paid-highway : Max 140ish KM/H and above that its kinda dangerous because the joinery is some areas can have a big gap and crack your wheel.

I have to use this highway to go to Bali. It is now under 2 years old.


Below is another part of the paid-highway which I will have to use too , to Bali.
The bulge like below, can break a wheel/rim easy, even at low speed of 80 KM/H.



Well.... now you guys probably realized why I am so **** when it comes to suspesion + steering + all kind of engine/tranny/DIFF mounts....... health of my car.
Its like a mine-field out there.

CaliBenzDriver

spaghetti highway
The company that erected that project copied the Mickey mouse foundations from Disneyworld coaster... ouch

Hope your wheels and suspensions survive the round trip... look forward to a couple spicy videos runs 🤠

Safe travels pal ✌️

S-Prihadi

, They want to save money by not making elevated highway super flat. If they make it super flat, majority of the support column heights will need to be increased.
Under 100KH/H its okey and since our speed limit is 80KM/H on paid highway, probably their safety vs $$ calculator deemed the risk is acceptable.

Thanks Cali...

S-Prihadi

Finally my staff managed to get thru to ZFAG AFTERMARKET office today, they are still working from home ( WFH).... no wonder.
Wished they used an auto voice recording to indicate alternative WFH number or re-direct/forward calls.

Will update soonest......

Arrie

Really looks like the shocks got a heavy impact so great that the too soft material of the upper end of the dampener piston rod gave away under the locking ring that also twisted as soft material allowed for that. The rod ends could have come thru the rear self of your car.

S-Prihadi

It is poor "seating" for clip/ring of the damper piston on the Lemforder, Arrie.

The 2,000KM Lemforder top mount & Bilstein B4 useage, is a very gentle use.
The original MB/SACHS top mount was the one being abused by the Bilstein B4 for 8,000KM ish, which included 20 laps at the circuit and Jakarta-Bali-Jakarta road trip.

1. Original MB/SACHS top mount : 0KM to 20,000KM with MB/SACHS original damper. 2014 to 2019.
2. Original MB/SACHS top mount : 20,000KM to approx 28,500KM ish with Bilstein B4 damper. 2019 to April 2021.
3. Lemforder top mount : 28,500KM to 31,xxxKM with Bilstein B4 damper. April 2021 to last week.
4. Last week, 31,xxxKM ish to now. Back to Original MB/SACHS top mount and new Bilstein B6 damper.

S-Prihadi

So, I managed to speak to the ZFAG/Lemforder PIC, passenger cars sales.
They saw the photos.

I also bought 1 more Lemforder 34909 01 from the official store provided by ZFAG/Lemforder PIC.
















The 2 units I bought in April 2021 is not a fake, they are genuine.
The Lemforder 34909 01 is what it is = CRAP...
Either that sandblast looking coating causing dimensional error or indeed the machining of the ring/clip cavity is poor accuracy...or BOTH.

I dont want to waste my time arguing for replacement, unless it is MB original one ...LOL.
They are very nice people the ZFAG folks. All 3 of my Lemforder 34909 01 is German made and not from some China factory.

So case closed.
I would probably now would not even consider arms/links from Lemforder.


End of Report.

Arrie

S-Prihadi,

I don't quite understand your last post as it makes me think your problem is (or was) with the top mount of the shock absorber. By the pictures earlier I replied as I think the problem is more with the softness of the piston rod and forgot to mention also with the softness of the locking ring. Those mounts look the same to me other than the two Lemforder mounts do not show the nut being tight against their surfaces, if I understand how these are put together.

I would also measure what is the outer diameter of the recess where the locking ring goes to as the ring should be kind of tight or snug fit in it. The cavity outside diameter is the support for the "cut" ring so the ring stays together and won't open up letting piston thru it. Also, the fit keeps the ring in middle and won't let it move that would make the ring "hand" on edge of the hole and allow it to twist thru the hole what actually is that looks to have happened. But I think the piston rod material is very soft, which you can see in your early pictures of the "mushroomed" shoulder of the rod.

I think you should call Bilstein over this as for me it looks like it is the piston rod material issue, not the Lemforder top mount unless that locking ting cavity outside diameter is too big.

S-Prihadi

Hi Arrie,
I can't measure the cavity ( recess) for the damper's ring/clip on the top mount, be it Lemforder or the MB/Sachs original.
The steel assy which has the cavity, is too deep inside the rubber casting/moulding, need to burn away the rubber and try to salvage the cavity to measure it.

At a glance it does seems Bilstein's ring/clip is "soft" as such both ring got bent, but that is not what actually happened.

The ring/clip on the damper's piston is small, very small. This ring/clip has to sit well and very flat and snug fit to the cavity for it on the top mount.
The cavity itself has to be accurate for both its outer diameter and inner diameter.

You are correct when you mentioned below : I am assuming you are speaking of the cavity.
Those mounts look the same to me other than the two Lemforder mounts do not show the nut being tight against their surfaces, if I understand how these are put together.

Because the Lemforder's ring/clip cavity is not dimensionally accurate and very much likely is not super flat compared to MB/SACHS one, the pressure applied to the ring/clip is un-even. This is the root cause.

The load applied to the ring/clip of the damper is at least 22kg at low speed and higher than that at high speed.
The 22kg or more is the value of the resistance of the damper piston towards a downward push or compression.
Downward push ( compression) of the damper is when the ring/clip works againts the cavity of the top mount, this is push load duty.
During rebound the damper's nut with nylon is the one doing the work and that is with the upper side of the Lemforder top mount flat steel area, this is a pull load duty.





Due to such small surface area of the ring/clip , any push type working load to it has to be equally distributed on its surface.
So the cavity at the top mount has to be really machined well to mate with the ring/clip a 100%. The cavity can not be chamfered/angle in any way.
Cavity can't have any coating which which cause un-even pressure to the ring/clip.
Cavity's inner diameter must be accurate as in not much bigger than neccessary, otherwise less surface area in contact with ring/clip.
Cavity's outer diameter must be accurate as in not much bigger than neccessary, otherwise the ring/clip will move around.







The bore accuracy of the inner diameter of the cavity, is reflected when we see the top mount from the top view ( where nut with nylon will sit )



The bigger the inner diameter ( poor accuracy), the worse it will be for the ring/clip.





Above is pressure point on the ring/clip, which require good surface finish and flatness of the cavity at the top mount and very importantly dimensional accuracy of the cavity ID ( internal diameter ) and OD ( external diameter ).

Too big an Internal Diameter of the cavity bore, the ring/clip will receive less load at where load is actually best at.
Left picture of the damper's piston shaft, ID line in red shows that it is the best load area because the piston shaft get to support the load too.

Poor accuracy + whatever is wrong with it.... of the ring/clip cavity dimension of the Lemforder has caused more pressure/load on the ring/clip at its OD green line and
also not equally loaded towards the entire diameter of the ring/clip. This is why the piston shaft holding the clip is damaged only at some areas.
If we image the ring/clip is a 330 degrees circular surface area, Lemforder's cavity poor accuracy probably only applied load to less than 60-100 degrees.... simple speak.



I agree with you Arrie, at a glance we think the Bilstein is the weak link.
Fortunate for me, this Bilstein B4 has work with the MB/SACHS top mount for 8,500KM plus at much severe work load and its ring/clip or the piston shaft has no damage.
It was the next 2,000KM of non severe duty, the same Bilstein B4 work with the Lemforder and disaster happened.

If only 1 side of the damper say LEFT one has a damage ring/clip and the wounded piston shaft and RIGHT being OK, that means I screwed up.
If both got the same damage and in the same profile of the damage, hhmmmmmm.... we start to investigate.

To satisfy our curious mind, when I get back from Bali or about 3,000KM of quite severe duty on the MB/SACHS with the new Bilstein B6 which is 12KG harder ( 34KG vs 22KG) to press over Bilstein B4,
I will inspect again the top mount and the ring/clip of the Bilstein. B6 or B4 share the same piston shaft and same ring/clip.

S-Prihadi

I forgot to mention, MB requested only 28Nm of torque for the nut with nylon for the damper's shaft .


28 Nm is not a lot and MB expects high machining accuracy on the components to prevent the "play".
The way the damper vs top mount working harmony is like mini impact drill. Push-pull so often following the road surfaces at minimum 22kg of compression and more at high speed.
The damper's rebound KG value I do not know, I can't measure that.

Arrie

S-Prihadi,

If you can't measure the ring clip cavity diameter then you can take the ring clip and put it in place without the piston rod to see how loose it is to move around. It seems the ring clips sit quite tightly on the piston rods so they might be slightly bigger when in place on the piston rods but you can measure then installed and not.

The pictures from your first email below show the markings on the ring clips on the cavity surfaces and it seems to me the impression area is quite even width around so this speaks for the ring clips not moving too much around so the fit looks to be correct but positioning the ring clip in the cavity will show how loose it is to move around.. You mention a chamfered surface in the ring clip cavity but I cannot see this in the pictures? The cavities to me look fine.

The right side picture shows the hard impression where the piston rod material held up and where the top mount carried the highest force when rest of the shoulder "sank" due to soft material. This top mount had to experience quite big deformation without cracking so for this I think it is made quite well. Or have you checked that it did not crack?




The second set of pictures below again from your post shows the top of the damaged piston rod. The shoulder of the rod against the clip ring has compresses the thickness of the clip ring, i.e. 4-5 mm. This is a serious damage and I believe this is the sign of totally failed material. This piston rod material is WAY TOO SOFT and this is your root cause for trouble. If the rod material was hard enough a deformation as big as in your picture would make it CRACK. When material can deform this much without cracking it is much too soft to carry the forces it is supposed to carry.




Again, your problem is not with the top mount from Lemforder unless the ring clip cavity OD is so big that it allows the ring clip to open too much to let the shock absorber rod thru it. The problem is with the Bilstein shocks.

The pictures of the shock absorber's top end shows very severe deformation and this can only happen by the material being too weak/soft. The piston rod should buckle before the end gets damaged like this.

Another problem can be that the ring clip material is also soft but the root cause here is the soft/weak piston rod material.

Wonder where your Bilstein's were made at.

Edit:
I have to add that the ring clip material is also very important as if it is too weak it can twist around the whole piston rod and if this happens it opens up the hole for the piston rod to fit thru. Looking at the pictures of the damaged ring clip show only the end of it bent so perhaps it it not twist too much...?

S-Prihadi

Them Bilstein B4 are all made in Germany, as per the body stamping and box ....not Planet Mars



Yes, I done the new-clip into cavity test , before I installed the Bilstein B6.
See how one end (top one ) of the ring/clip is not sitting properly (a bit hanging in the air ) in Lemforder cavity while it sits pretty at MB/SACHS.

Seems so minute a a difference yes ? BUT, the big but is.... the ID of the clip/ring at its opening/jaw is where it is critical and need to be correctly supported... the jaw is the weakest part of the clip/ring for sure.


I looked at my photo files slowly and found this :

Above is so obvious that while clip/ring sit in cavity, the mating to the cavity is not perfect.
The rubbing off of the coating shows. As for the minor damage on the top mount, I think that happened when clip/ring got bent and got push backwards opposite to its jaw/opening.


Below is odd. Seems like the cavity is twisted or what ?

Arrie

Your left mount picture looks like the ring clip was not seated properly n the cavity, like the ring was hanging on the edge of the machining and then was pressed in the cavity and it took some of the edge in with it?

But based on the damage to the piston rod end I still believe there is an issue with the piston rod material. If you still have the original MB dampeners you could do a file test to see how a file bites in the materials. Just don’t do it n the area of the surface chrome on the rod. Do it at the bottom of the thread where the ring clip sits.

S-Prihadi

You should read the post from the start and read slowly to absorb the information. You seems to be a speed and skip reader.
No offence meant Arrie.

You forgot that the Bilstein B4 clip/ring was totally un-harmed for 8,500+ KM , which included abusive 20 laps driving at the race track and 3,000KM of heavy load Jakarta-Bali-Jakarta trip, but using MB/SACHS top mount.
And then nice soft drive for 2,000KM same Bilstein B4 but using LEMFORDER top mount and Bilstein B4 ring/clip got raped .... LOL.

Yes, when first dismantling 1 of the Bilstein B4 and I saw its ring/clip damaged I initially thought it was my installation fault back in April 2021.
When both Bilstein B4 ring/clip had the same fate....hhhmmmm ....

Your left mount picture looks like the ring clip was not seated properly n the cavity, like the ring was hanging on the edge of the machining and then was pressed in the cavity and it took some of the edge in with it?
Yes it can be intrepreted as so..... but my hypothesis was different
Well, you can have your own assumption and myself have one too.

1 - I made sure during install that the ring/clip sits well at damper piston shaft.

2 - Once ring/clip sits well the top mount comes down and all good. And then torqued down.

3 - A misaligned ring/clip as you suggested will cause wobble and noise even during torquing down to 28Nm and the few times full compression press down test I did before installing
the damper + top mount on the car.

To me is simple. Looking at how little surface area the ring/clip sits on the damper piston shaft, a high accuracy ring/clip cavity dimension must be provided by the
top mount. Otherwise its a a crow-bar effect, the ring/clip get push down more by top mount at the outer diameter of the ring/clip where we actually want the inner diameter
of the ring/clip to get that load....as underneath the inner diameter is where the piston shaft helps.

This ring/clip is not a simple nut with washer equivalent load say on other component like a stabilizer link, where a washer being the ring/clip equivalent has full support and full contact on both faces.

I sometimes wonder, why would not SACHS the OE make a 3mm fatter piston shaft diameter while maintaining the same small diameter threaded end of the shaft,
as such the ring/clip can have near 80% or more of its bottom side supported by the piston shaft and less crow-bar ( angled ) push down effect generated by top mount
ring/clip cavity. The ring/clip is a CHEAP bearing.... sort of, that is it's function. Rear suspension has no steering system, but it still needs a tiny bit of play for a few degrees of spin.

If support is the only need and not ability for minor "wiggle", no need to have a ring/clip.

Front strut has bearing, real bearing at the top mount assy and no need for ring/clip at the strut piston's shaft.


Lets wait 2 more months.
Will do a Bilstein B6 teardown and inspect its ring/clip and let's see how the MB/SACHS top mount condition too, now that 12KG extra work load at low speed will be upon the MB/SACHS top mount
and much more KG work load at high speed.

I need to buy the MB/SACHS top mount as spare, it needs to be out of service by +- 40,000KM or about 8,000KM more.
Must get the SACHS aftermarket version. MB version need to buy as complete damper + bump stop + boot + top mount. I dont want MB damper.

Senecat

OR, just stay off that nasty bridge from now on! You do provide a wealth of info with your posts, Prihadi, much thanks for that!

V12mrinc

I agree with you 1000000% !!! Just had to return both lower thrust arms to FCPEURO for fitment issues with Lemforder. My indy ridiculed me for attempting to by “cheap” parts but I was under the impression Lemforder was OEM.

My indy compared the Lemforder to the removed arm prior to installing and admitted, visually the Lemforder appeared identical to original part but once installed the opening where strut connects to the thrust arm was too large.

Prior to this, I had a poor experience with RockAuto suspensia brand on fitment for inner tie rods (outer fit good) so I thought I’d try Lemforder…

Seems like with suspension parts it’s a gamble not biting the bullet and going to the stealership.

S-Prihadi

Thank you V12, at least now I know even some of Lemforder arms are dimensionally OFF.

Arrie

I guess I was lucky as the lower lemforder control arms for my S550 werew made correctly.

I also thought Lemforder is the OEM for Mercedes. Is it not???

V12mrinc

Hey Arrie! Lemforder, based on what I’ve read manufactures for MB directly but there’s this weird gray-area it seems Lemforder parts are made with MB part#s but not always the MB logo since it appears they have a non exclusive licensing arrangement.

As I get more info I’ll share. I mean I’ve heard nothing but good things before I made my purchase and my guess is that maybe those of us that had fitment issues are the 1-in-1,000,000.

Not even a blip in the grand scheme of things in reality, but to those of us who’ve pulled the “short-straw” and received parts from the “slightly irregular” bin, it’s just reassuring to know we’re not alone and not actually Crazy

(Well not cray-cray in regards to the fitment assessment anyway lol.)

Arrie

What is the latest in your saga with these top mounts? Did you get it all working now?

S-Prihadi

I am still re-using the MB original top mount for now, for the new Bilstein B6.
Will only able to re-inspect the top mount December 2021 when car is back in Jakarta city, now me in Bali city.
The top mount been quite "abused" by the Bilstein B6 for Jakarta to Bali run and will be the same torture at least.... Bali to Jakarta return trip.

Arrie

Yeah,

some roads for you are pretty harsh. I have visited twice in Jakarta area, where it is not all that bad but the area in around Pekanbaru, where I visited several times, is a bit different story…

andynmaas

Arrie I born 1959 in Pekanbaru where oil company Caltex become Chevron and now Pertamina. Before 1980 the road made of rude crude oil as top layer so on rain it slippery like ice skating ring. The one you see maybe the road between pekanbaru and which corrupted sa bad so quality was bad. It getting worse because of truck loading ton of log make road so bad. Now toll road is completed do it 10 times better.

I did used same combination for e350 2013 4 matic using Bilstein B4 for front and B6 on rear replaced around 80k miles because after hit large pot holes my tire worn so bad it chopped irregularly. I am not mechanically expert as Prihadi but I am able to replace it without problem and it ride better than oem and fix problem with tire even without doing alignment. I am about to replace front top mount using Corteco bought from fcp euro but after examining compared with oem I return corteco and just use original eom top mount. I thought corteco not as good as oem because when i rotate it too stiff. So my install using original old oem. I had no problem until now at 178k miles. I think bilstein had no problem and it way better than Sach.

S-Prihadi

I hereby confirm that Lemforder Top Mount , all 3 I got, genuine , as per this thread..........are GARBAGE !!!

Jakarta-Bali-Jakarta and some other location in between. Harsh driving too with lots of high-speed and suspension "jumping".
4,000KM+ on the old original SACHS top mount ( 34,000+ KM today ) with a firmer Bilstein B6..... flawless, no damage to the Bilstein C clip/Ring.

Compared to 2,000 KM city driving for the Lemforder, slow speed, a weaker Bilstein B4. Ruined C Clip/Ring.


As promised, inspection after the Bali trip :




RIGHT REAR - Below









NOTE :
I am too lazy to remove the top mount.
The boot/trunk plastic liner at the lock mechanism/bumper is fragile. I already broken one of the plastic rivet holder ( U shaped ).
So I use my Teslong boroscope instead
.