EPS Control arm snapped

Just a heads up for everyone. I have a 2003 C2 Cab. I tried to save some money and bought the EPS lower control arms with the polyurethane bushings. Installed them in April and had one snap at the head today. Luckily I was a block from my house when it happened. Now I’m going to do what I should have done in the first place, buy the OEM arms.

The limited range of motion that the poly bush in these provide never made sense to me, i'm not surprised this snapped. Good to know this didnt end too badly and you got home safely.

They need Johnny Joints in there,, rubber mounted ball and socket, and totally re-buildable, but only possible with built up tubular arms..

I�ve been running them on my car for 4 years - no problems. Just because a (1) part fails it doesn�t mean it�s a bad design. If there are a rash of failures, that�s a different story. More likely it was a defective/damaged part before you installed it, or it wasn�t installed/torqued properly (not sure if that would cause it to break though)... in any case, glad there was no other bad result...👍

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I followed the torque values in the service manual. You are probably right that it was a defective part. It happens. They do have a five year warranty, but I�m a little worried about it now. Just going to replace both with OEM and be done with it.

I don't blame you - it's not like the oem arms are crazy expensive or anything! I'm sure EPS/Vertex will replace it, as it's pretty obvious it was defective. Good luck

um - you're talking the trailing arm? oem arms have solid bushings in there, eps have poly which allow more movement than suspension designed for. i would suggest design flaw.

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They are talking about the diagonal control arms, or "tuning forks".The OEM have integral Heim Joints, the EPS has a poly bushing...

though that's what i said?

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If it was a design flaw, I�m sure that many more would be breaking. And the oem arms (�tuning fork/ lower control arms� not trailing arms) do not have �solid bushings in them�...

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ok, here we go ... not a design flaw because only one has broken? for every broken arm reported on the internet, how many have actually broken - 10? 100? 1000? how may eps arms have been sold? 10? 100? 1000? perhaps every single arm of the 10 sold have broken and we have only heard about one? perhaps not. what i do know is that the oem arms do not break. i am sure a few have, but i also know MILLIONS have been sold. imaging the lawsuits if there was even a 1% failure rate (broken suspension component at 100 mph?)? not a trailing arm? well, here is a link to the exact same component that does the exact same thing only on a boxster. what does eps call it ... a trailing arm: https://www.europeanpartssolution.co...ng-control-arm oem is not a solid bushing? here is a link to the video from eps about their product where they discuss the oem plastic bushing used (albeit as a lining to a ... heim joint; points to pt3 in the semantic battle, as well as the range of motion bit - i got it backwards ...): You Tube i'll leave the rest up to y'all to decide if this product is a good one or a bad one. i know i would not put one on my car.

Not street, but I've seen many more than one BMW and Porsche arm fail with track use... typically they don't fail catastrophically you just start seeing cracks.. The most notable ones are the M3/M5 Aluminum arms..

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From the video you've shown it looks like the OEM bushing actually allows for a lot more movement than the EPS 'upgrade', the latter not being able to move much at all, and 'springing' in directions the original part was not intended to produce forces in. Due to that poly bushing introducing significant resistance in directions the original suspension was not designed to resist, the arm will be continuously laterally loaded, more so with every bump. It's like they completely deviated from the original concept of that part, just so they could stick some colored poly in for extra $$. I'm not surprised it broke.

That video scares me...completely different function between designs. Heim joints (OEM) are used when clevis joints don't provide enough degrees of freedom through the range of motion. I would stick with how Porsche engineers designed it...their engineers are pretty good from what I hear.

The EPS arm is not as wide/tall either. Didn�t notice this when I installed them. The other is the OEM arm I took off the car.

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yes, my bad, i was only talking to 50% of the issue. the oem arm is designed to not move under tension/compression, vs the eps which does (the hard plastic/teflon heim joint liner vs poly bushing). eps would introduce caster change under load (as a track guy this is what is front of mind for me). what i missed as you've all noted is that the oem unit is designed to articulate much more than the eps, so that the eps unit loads under suspension compression/extension in a manner that oem does not. and this is most likely the reason for failure. i mean, a quick look at the design of the arm (a simple 'I' beam) and it is quite obvious that it was not designed to be loaded in the direction that the eps bushing loads it.

Could it be a fake part made out of Pacific Rim pot metal?

Wow, that's a significant difference in material, no wonder it snapped.

I've have had the EPS lower control arm on my 2003 C4S for three years and 12,000 miles. I just went out and looked for cracks but happily they look fine. Since the failed part was almost new, it must have been a defective casting on the arm. I suggest that the failed part be sent back to EPS for their testing and comments. I also see Amazon offering this part at half price compared to directly from EPS. Are these fake copies? I replaced my original OEM arms because they made a loud knocking noise crossing pavement cracks. It was bad enough that my wife made disparaging comments every time we took the car out. It was either fix the problem or sell the car.

I ordered a genuine Porsche AOS from Vertex via Amazon, it was listed as fitting my 02 but what I got was for a Boxter. I emailed them and eventually got the right AOS after getting a second Boxter AOS sent out. They sub'd an aftermarket unit instead of the genuine Porsche part. They eventually made it right. Good customer service, but poor quality control...

Watching that EPS video with the volume muted looked like they were explaining why the design change caused the arm to fail there....all the way down to the flexing the arm back and forth in the vice at the end...yikes!

Mine snapped yesterday, lasted 16.000 miles. I was lucky as it snapped at low speed a few days before a long roadtrip up the CA coast. I have never tracked the car, this is from street use only. Please do not install these as serious damage can occur. Here is the response I got from the manufacturer: "this is a first for us regarding this, we have never had any problems with our control arms, only when the customer crashes or runs over a corner when turning, that also happens with the factory arms." Thus they offered a replacement in lieu of a refund. Pelican parts came up with the same response. Needless to say I am not replacing this part with the same brand. European Parts Solution Control Arm after 16k miles

Look at the one review left here .

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Yeah, they are completely lying if they say it�s the first time they heard about this. We all know about this problem, yet they don�t? Yeah, right.

yep, using a stiff joint there is not a good idea

My motto is "OEM is best"!

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It's highly possible it was a casting that had porosity reducing it's integrity, but looking at the OEM vs. EPS I don't see why anyone would change to the EPS design. Is there an "end game" compared to OEM? To me there's virtually no benefit besides possibly paying less, but as with most, you get what you pay for. In regards to the Amazon, there are so many fake copies of all types of products on there now days (colognes, car parts, clothing, etc.) that it's not worth assuming the risk because it's become such a crap shoot. Purchasing through a reputable dealer is better, and you may have to pay normal freight charges, but generally less likely to get screwed over with a fake product.

The cross section of that arm is clearly designed to support loads in tension; that bushing effectively turns it into a spring, and the arm now has to support loads the arm was never designed for. (The last thing you want to do is turn that joint in to a spring.) Stick with the OEM style joint. I've always thought one of the greatest risks to the general public are cad jockeys who think they're engineers because they can model on autodesk/solidworks.

The problem here may be two fold. The casting may not be as sturdy or may have had a flaw in it. But this unit also has a totally different type of bushing which is probably not the best design. As for the Porsche control arms they are over priced due to the Porsche name being printed on the box. Porsche does not make their control arms, they source them from another source like many of the "Porsche" labeled parts. So who actually makes their control arms? I have used the Meyle control arms on my car and have never had a problem with one is years of use. As an aside on "Porsche labeled parts, several years ago I needed a new AC compressor for my car. The price at the dealer was about $1,800 in a box labeled Porsche. I went to Rockauto.com and bought the Denso unit for $270. When I removed the original one it was the exact same Denso unit. same model number, configuration, etc. as the one from Rock Auto. So the Porsche one was amost 6.5 time the price. That is crazy!!

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I wish it was like that with the coolant expansion tanks! I just bought an OEM one for $450 when an aftermarket one is $50 dollars. The aftermarket Non - OEM one BBi installed in my car for $650 lasted less than a year. Some things do make a difference when they are OEM. I would definetly try the Mahle suspension pieces. They come with a warranty.

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I was (still mostly am) of the same opinion but let me offer you -and others reading this- my perspective having run repair businesses. My experience has been that quality control is better on parts that come labeled and in manufacturer/dealer boxes. More than once we have had parts arrive non operational (new in box). Once on a Mercedes we replaced 4 cam actuators directly from Pierburg (O.E. manufacturer, same part number etc), arrive non-operational. Only after paying extra to "get them in Mercedes branded boxes" did we actually receive parts that worked as designed. I would personally in general still use O.E. manufacturer parts attained outside the dealer network on my personal cars but it does seem like there is a difference none the less.

So they are saying that normally when there manufactured arm breaks, it normally causes an accident? sorry that�s just poor manufacture and lack of testing and quality control! AVOID and the argument that it might only be 1% well that�s great as long as I�m not the one who ends up dead, in my 170mph supercar. similar thing I had with wheel nuts supplied without the washers, just because they fit, doesn�t mean it�s the right and fit for purpose part. thanks for the heads up

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it doesn�t have to be a fake part to have this problem, most companies manufacturer in the China, but the quality control has to be so good. I know loads of companies from Europe and the USA that have had production issues, with Chinese castings. often the companies do make really high quality parts ( as well as cheap parts ) but mistakes and supply of material and also knowing what to do when there is a process issue or failure is not always there. one issue I knew of ended up with the heads pinging off of m80 bolts, yes 80mm diameter all torqued up which was fine until the oil rig was out at sea!

It�s just a bad design that is not allowing the arm to rotate up and down with the suspension. This causes the aluminum to flex and weaken and crack, that�s it.

Yikes!! My EPS control arm broke like you guys said it would. The original OEM arm made a clunking sound after 32K miles but that was just irritating. This failure was dangerous. Luckily it broke just as I was pulling into my favorite repair shop (Gerber Motorsport in Seattle) after a 200 mile cruise through the boonies. I could have crashed or been stuck far from home. Naturally I am having them put in genuine parts.

I worked at a university for a while and we had a material science program for Mech engineers, we had a SATAC materl stress machine that stretched or twisted or whatever any sample you put in it, those are classic fatigue cracks.. and based on their angle and look its definitely being stressed in the thin direction.. I am not a mechanical engineer but I have had a lot of cool toys to break stuff with in my life...

Anybody of the gentlemen experiencing this failure considering to file this with NHTSA? I bet they'll be pulled off the market in no time...

There is no dot number on that bushing. Its sold a race product with, im sure a fine print disclaimer. U r your own warentee station when u start to mod beyond factory.

Whelp, guess I�m the new addition to the growing number of folks who have had the EPS control arm linkages fail while installed. Mine lasted 4+ years and I still have a few days to return to manufacture to honor that 5 yr warranty. It just so happens that the failure occurred during some hard braking I did to avoid another accident that had turned the highway into a parking lot. Anyhow during the hard brake I heard a loud pop and snap sound followed by smoke which I initially thought equated to a blown tire. After slowly merging out of the road and moving to the shoulder I realized the car handling was off. As I prepared to make a tire change I saw that my tire was actually in one piece and good, except that the plastic lining of the wheel well was melted like chocolate on a s�mores. 😣 Then after further inspection I saw the nasty snap on the control arm. Sad ending to a nice drive, especially seeing the 996 being ferried home on the flatbed tow truck. �We suck again.� 😞 Anyhow, looks like I will be switching back to original parts.

Minor update: I'm researching suspension replacement parts and came across these EPS pieces, which led me to this thread. The Amazon comments section has 4 reports of them snapping. 3 reports in the 1 star section, and 1 report in the 2 star section. Amazon Amazon

Spend the extra $$ and upgrade or go with stock OEM parts.

I hope to revive this thread so that others might update their experiences with the EPS control arms. Mine snapped at the bushing end. My experience was as exactly described by �schnappi�in an above entry. These front control arms are of poor design and unsafe. Do not buy these arms

Not to dissent, but I have 4 years and 25K miles on mine without issue.

A control arm should never, ever catastrophically fail. Barring a direct impact from a rock or curb, or a collision impact…just effing no! Try pushing a shopping cart with a bad wheel and multiply that mass by 60 and add 100 fps velocity. Only bad things will happen. Catastrophic: involving a sudden and large-scale alteration in state.

I've done a lot of "link" based suspension work, all I have to do is look at the EPS arm and I'd say NO. Links need non binding travel to do their job, whether rubber or ball or hybrid. The EPS doesn't have that it has 2 parallel contact surfaces with no obvious room for travel. Also Neoprene is not for every suspension joint, I've fixed a lot of suspension "problems" moving back to stock style rubber. Note this is a summary of opinion not a detailed analysis,, I am not an engineer I am a guy who's addicted to working on motor toys..

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Replace them while you are ahead for OE(M) ones with a spherical joint.

Failure could be catastrophic. Why risk it to save a couple of bucks. Makes more sense to go oem or a known manufactured racing part that has proven its worth at speed under extreme stress. Don't get why anyone would want to sub-optimize.

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I Just ordered a pair of Meyle arms and was sent the EPS instead because the Meyle were out of stock. Thanks to this thread for saving me from what would�ve been a big mistake! Looking into this here and elsewhere, I�ve found 10+ instances of broken arms, all from casual street driving. I sent these back and went OEM. Sounds like EPS is waiting for class action, and I�ll be glad not to be a part of it. Thanks guys!