DennisG01

Sometimes you gotta REALLY push/pull hard to get a joint to make a noise by hand. I've seen mechanics use a long breaker bar as leverage while they look/feel for the slightest movement.

Max Blast

Have you put a pair of chassis ears on the front suspension components? That will isolate the source of the knock and allow you to identify it.

Also, Arnott struts may ride well but I suspect they start failing internally much quicker than the OEM ones - one failure mode being a audible knock or clunk.

DrMel

I haven't tried Chassis Ears yet. I'll give it try though.

If the Arnott struts failed then they were DOA since the clunking started immediately after they were installed.

Max Blast

Well, unless you loosened anything else when putting these in, I'd say you've narrowed down the list of suspects to those struts.
Yours might have been DOA - mine began knocking around 20k miles but ride just fine.

I've been in contact with Arnott reps and they tacitly acknowledge a lower service life than OEM, which is why their warranty is very generous. (As long as you can provide proof of purchase).

Good luck, I'd start with miking the struts up and going for a short slow speed drive.

TX07GL450

Mel, did you get it fixed? what was it?

DrMel

Unfortunately, No.

I need to get a set of Chassis Ears. We've been dealing with the rattle for now. I'll update soon hopefully.

-Mel

kombifan

did you replace both front stabilizer links with mb parts?

Bushings are also known to fail and control Arms too. But if they’re not mb stabilizer links they can cause the noise. I replaced hem myself with rein ones thinking it was all good , but the noise came back after a couple months so my dealer ended up replacing them both

DrMel

Back in Jan/Feb, I replaced both links with Detroit Axle brand. They caused new popping and clicking sounds AND the heavy rattle was still there. I returned those links and put the original ones back on. I haven't tried replacing them again with MB parts. I'm leaning towards the control arms (particularly lower control since the sound is such a deep heavy rattle) but I want to get chassis ears on them to determine if it's upper, lower, or both. Either way, it looks like it'll take quite a bit of breakdown to replace the control arms. Has anyone done those replacements on jack stands?

kombifan

really. Try replacing the sway bar end links again with mb parts.

DrMel

Went to my Indy today and much to my regret the front passenger strut is failing. I replaced the air shock in December and I'm guessing the strut somehow failed from being disassembled. At this point I'm thinking I'll replace the entire assembly. I haven't seen just the strut for sale. And since it's not the shock that's having an issue, I'm not sure Arnott's warranty will help at all...

While I've got it all ripped apart I'll do new OEM end links and maybe upper control arms.

kombifan

🙁 I even recommended getting the full unit.

You could try contacting arnott to explain your situation. Maybe they'll give you credit for the upgrade to the full unit? Doesn't hurt to ask.

DrMel

Agreed! The full unit is the way to go. I should have spent the extra ~$150 the first time.. we were getting ready for Disney and I wanted to save every nickel

Live and Learn

eric_in_sd

Just to help everyone out, especially the newbies:
Strut = whole assembly
Air bag that surrounds the top of the strut = air spring
Piston-like thingy that is inside the strut, and which you don't see = shock / shock absorber / damper

kombifan is right; it couldn't hurt to ask. Maybe mention that you have heard such good things about Arnott from the MBWorld forums, but you're tempted by their competitors' lower prices ... and you really want a company that stands behind their products etc etc etc

Punishment, meet glutton. I wouldn't do stuff unless it's a known culprit, or cheap and easy.


It is a mystery to me why the end links are so unreliable. This isn't rocket science. It is possible it has to do with people installing them with the front end lifted? There is play in the holes in the swaybar and lower control arm.

Maybe if they had zerk fittings and you could pump grease in there once in a while?

I got 20k miles out of a set of OEM links. I just got 2k miles out of a non OEM. This is infuriating because these things should literally only be under stress when the vehicle is cornering. I ordered another pair non OEM; let's see what happens this time. I think I'll also try to do a failure analysis on the clanky one.

DrMel

Thanks for clarifying. Yes, my shock has failed. I replaced the air spring in December, now I'll be replacing the entire strut (assembly).

I'll try to sweet talk Arnott.. here goes nothing

DennisG01

I thought the front assembly consisted of a strut and an air spring? The main, metal, cylindrical thing being the strut - no shock at all. But the strut does go through the middle of the air spring. Meaning, like many cars' front ends, the front suspension consists of a strut/coil over spring... but the Merc uses an air spring instead of a steel, coiled spring. Plus, a strut is a load bearing component of a suspension system, whereas a shock is not. A shock ONLY dampens bouncing. A shock would be used in addition to air/steel springs or torsion bars, but not in lieu of a strut since its not meant to hold weight. Please correct me if I'm wrong, though!

eric_in_sd

You're WRONG WRONG WRONG

heh, it's been a hard day

I don't think there's a terribly strict nomenclature. However, Arnott sells a "strut" which includes the whole enchilada, spring and everything.

I think if you removed the spring, you'd have the strut body. The thing inside it is called a shock cartridge. They are different from a normal shock absorber in that they need to encased in a cylinder. Most don't encounter these because they're messy.

The whole thing, strut body plus spring plus top plate, could be called the strut assembly but people usually shorten it to strut.

Whenever I've bought a strut, it's invariably been the whole assembly.

eric_in_sd

To Dennis's point, if your shock failed you'd get all kinds of weird bouncy bouncy stuff. It can actually sound like a failed wheel bearing because the tires cup and make a roaring noise.

fkong777

I let my strut go to the end after 2 months of dropped front end in the morning. . One day it just went. Fortunately I was near my house and it could still drive.
Just so you can see a failed front air spring. I took pictures before I return the core to Arnott.
OEM MB strut fail.

eric_in_sd

Holy moly that's a thing of beauty.

DrMel

Problem solved folks. Replacing the entire assembly eliminated the rumbling. I installed Delphi end links from FCPeuro as well. Maybe it's an illusion but the steering is tighter now.

I tried to send in the Arnott's Air Spring since it's only 5 months old, but they wouldn't take it since I purchased them from Amazon and apparently they stopped selling direct to consumer at the end of last year. Now I'll try to sell the spring on eBay. Arnott support also mentioned they don't sell reman versions of the strut anymore and they aren't buying cores. I'm assuming they're winding down production of the air suspension parts for the x164.. that kinda concerns me.

kombifan

Perhaps arnottdoug can chime in on the changing production of the struts?

Maybe thrr're switching over to their new struts only. Maybe they found the problem causing them to fail earlier.
Maybe they found a unicorn. 🦄

eric_in_sd

When I checked with them a year ago, they had changed the design. In fact they were kind enough to send me a replacement purely because it was the old design.

My guess is they have enough inventory of cores now, it's not worth shipping them.

Good to hear you got it sorted out. Arnott to the rescue.

Yup497

They purchased my OEM front cores a month ago.

When I called and spoke to their support team, they stated as long as I have my receipt from my Amazon purchase, they will still guarantee them.

I purchased a new pair of air struts. Not sure if that matters.

DrMel

Maybe you squeaked by just before their needs changed. Or do you have ADS? Those are still being purchased. Here's a full list on their website http://arnottinfo.com/files/Arnott_C...OE_Numbers.pdf
And technically the air springs I bought from them didn't fail, it was the OE shock that required me to swap the entire assembly. It was gonna be a stretch for me to convince them to replace my whole assembly.

arnottdoug

Arnott is still purchasing and remanufacturing the Mercedes-Benz OE ADS struts but not the non-ADS ones. Both models have an Arnott new strut with zero miles and and no core deposit. While the Arnott new struts for ADS models were tuned to have an excellent ride and provide both the luxury and auto leveling of air suspension - they do not work with the vehicle's ADS controls. We do plug into the ADS system but only to provide a sensor that will turn off any ADS dashboard warning light.

As you noted, recently we moved away from selling direct in favor of continuing to build our three tier distribution modal (Sell to distributors, who sell to installers and resellers, who sell to or install on end user vehicles). This is typical for auto parts manufacturers.