Koni sway bar link bracket failure - Any coilovers available only for the front axle?

[inquirer]

I had a weird failure of a Koni Sport strut yesterday, specifically of its end link bracket. The car is a Mitsubishi Lancer 1.5L 110 hp.

Here is the story:

1. I had installed the Koni Sport struts on all 4 corners of the car along with upgraded front and rear sway bars and end links about 3 and a half years ago.
2. Shortly after the installation, when I parked my car on a roadside parking space, when stepping on the ramp there was a very loud metallic noise from the left front corner for no obvious reason.
3. I got the suspension inspected by a car mechanic who did not find any issues, but added a second nut to the end link, because he thought the end link nut had gotten just a little loose.
4. After that there were random metallic noises from the same corner of the car, but they were really sparse and most of the time the suspension was totally quiet. In all these 3 and a half years there would be no more than a bunch of these inexplicable noise incidents. And I call them inexplicable, because the metallic noise in all cases had taken place on subtle road surface anomalies, never in more demanding conditions for the suspension as someone would expect.
5. The last 2 days before the failure, these very rare metallic noises got more frequent and the bracket failed when I reached the garage shop, while driving on the ramp to enter the shop and get the suspension checked. As you can see in the attached photos at the end of the post the bracket did not snap at the welding point, but at the middle of the hole which is super weird. I'm pretty sure the bracket came with a structural issue that progressively got worse. It failed in a little less than 31.000 miles.

I contacted Koni and they said the 2 years warranty window has now passed, so they won't offer a new one as a substitute... They also told me to contact the local dealer, but I'm not sure what difference that would make.

I'm thinking to follow one of these options:

1. I will contact the official Koni service in my country to check out if they can attach a new bracket, while rebuilding all 4 shock absorbers.
2. If not I'm thinking of installing coilovers, but only for the front axle. The car has an aftermarket LPG kit installed and I had installed reinforced MAD springs on the rear along with the LPG tank, so I don't want to use coilovers that have standard springs in the back of the car. Are there any manufacturers of coilovers that sell them separately and not as a set of 4?

 

[KrisZ]

That sucks for sure. You can even see the rusty part of that crack, which means it was there from the beginning and just got progressively worse.

I’m not sure there is enough “meat” on that link bracket to weld it back on, but it’s probably worth a shot to consult with a welder.

 

[KevinMalone]

Interesting failure. Curious if the adjustable end links were set to the proper length at installation?

 

[inquirer]

@KrisZ

Yes, pretty sure it was there since the start and it was the cause of that super loud noise I had heard. The initial noise was loud enough to think that the strut had broken in two pieces, but that was followed by weird silence! Any noises after that were random and very rare.

Anyway, I don't think that bracket can get welded back on. I was thinking of unwelding the piece that's left on the strut and then welding on a new bracket. Even a custom bracket can be made by a machine shop for that purpose if Koni does not offer that piece as an available repair part. But since the Koni struts are gas filled - along with oil - I'm not sure the process can be done without removing it for safety reasons, so I guess the whole process can only be done by the official Koni service if they are willing to proceed with it... which definitely is not part of a regular rebuild.


@KevinMalone

Yes they were. To be precise I had initially tried to install the sway bars with the OE links. The front did not fit and I got one of fixed length and then in less than a month from the initial installation I put one adjustable ones in order to adjust the length with precision. I had to make custom ones for the RSB modified by machine shop in order to achieve the proper length.

 

[spasm3]

I'd replace those. Either warranty or even if not. I do some welding, not a pro, but i would not weld on that pressurized strut. I think those welds are done at the factory before the cartridge is in or pressurized.

If it did not blow up in your face, it would probably lose pressure and fail anyway shortly after.

 

[KrisZ]

Good point about the pressurized cartridge. Even if nothing catastrophic happens, the internal seals will likely get damaged from heat.

 

[inquirer]

Safety is always the first concern. As @spasm3 mentioned at the factory, during production the welding takes place before pressurization.

Obviously when Koni services their struts they remove the gas, but I guess they wouldn't deal with the welding part. I'm not sure if they can send me the broken strut back in order to find a welder to fix it and then send it back to them to continue with their rebuild.

 

[AZjeff]

I'll bet Koni wouldn't touch a strut that's been welded out of house. Nothing lost to ask.

 

[inquirer]

I agree. It's reasonable to think that they won't. Even if they don't care about the welding itself, I doubt they will send it back and forth for it to get welded.

My plan B is to find coilovers only for the front axle, but I'm not sure they sell them as a set of 2 or separately.

 

[slo town]

The failure of the end link bracket was because the ball joints on the link were not properly "centered" with respect to lock-to-lock steering angles. In other words, the ball joints were unable to pivot any further, thus putting side force on the end link bracket when at full steering lock.

I run adjustable anti-roll bars links on both my BMWs. "Centering" the end link ball joints so they don't bind at full lock takes time to set up properly.

Scott

 

[inquirer]

@slo town

The strut had made a very loud bang noise pretty soon after the installation without any probable cause, so I guess the bracket was problematic from the beginning.

To be honest, it's the first time I hear about centering the ball joints. The thread was looking straight ahead when I bought the end links and that's the way it was installed. By the way, the joints are very hard to move by hand.

Oh, and these are the links I have used: https://www.jom.de/en/drop-links-se...w-golf-5-vw-golf-6-vw-jetta-5-vw-passat-3c-vw

 

[slo town]

@slo town

The strut had made a very loud bang noise pretty soon after the installation without any probable cause, so I guess the bracket was problematic from the beginning.

To be honest, it's the first time I hear about centering the ball joints. The thread was looking straight ahead when I bought the end links and that's the way it was installed. By the way, the joints are very hard to move by hand.

Oh, and these are the links I have used: https://www.jom.de/en/drop-links-se...w-golf-5-vw-golf-6-vw-jetta-5-vw-passat-3c-vw

Just trying to clarify, I'm not throwing stones.

You say this was soon after an "installation" of some sort? I don't see any new parts in your pictures.

With respect to the end links, yes, a classic design and functionally identical to the ones I have on my BMWs.

Whenever adjustable end links are installed, make sure the ball jointed ends are adjusted so that they don't "bottom out" in the twisting sense during lock to lock steering inputs. When I've installed these I recall there being only small amount of additional end link travel beyond steering lock.

You have to check everything in both left and right full lock directions. It's been my experience that lock-to-lock end link adjustments had to be more exact than I expected. It's easy to misalign one end while tightening the other.

And of course, end link length is an important dimension to check.

IMO the biggest benefit of adjustable end links is that you can set the anti-roll bars into a neutral, unloaded condition. In every case where I've removed an OEM end link on a new and unmodified car there has been significant pre-tension on the anti-roll bar(s).

When I put adjustable end links in my E46 BMW I set the anti-roll bars (both front and rear) into a neutral position with my son sitting in the driver's seat with the door closed. That was the car's weight distribution when I'm driving it solo. Adjusting the end links into a neutral position makes for more equal left/right cornering performance. Often times a car has a "strong side". Doing this tunes that out, making the car more predictable.



Scott

 

[inquirer]

Soon after the installation of the struts and the sway bar I got a loud banging noise coming from the front left corner for no obvious reason. That was about 3 and a half years ago. You can read more details in my first post.

My guess from the series of events is that the plate was problematic from the beginning and it was the source of inexplicable metallic noises. Another thing that points to structural failure is the position it broke. It broke in the middle of its hole, while the welding is supposed to be its weakest point.

I will keep an eye for what the ball joints will do, when I will have the end links on the car again. But to tell you the truth, if a joint was out of its motion range I would expect the joint to snap and not the steel plate which in the case of the Konis is pretty thick.

 

[inquirer]

Just an update...

Since I took conflicting opinions about welding the bracket by different shops, I decided to order 4 new shock absorbers. This time I will install Tein. I'm still waiting for the order to arrive from Japan.