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Bilstein PSS strut problem

26K views 134 replies 28 participants last post by  poeter 
#1 · (Edited)
Hey guys, just an FYI. About two years ago, I had a Bilstein B14 PSS kit installed in my 540. New shock/strut mounts at the same time. Love the kit, handles and rides great, but after a bit over a year, I started getting a faint, intermittent knock from my front suspension. Figured it was time (over 140k miles) to start replacing much of the front end, so went ahead and installed new everything...center, left and right steering tie rods, new thrust arms with the Meyle HD bushing upgrade, new control arms, new end links, new sway bar bushings...everything but sub frame bushings. But the knock persisted. Had one strut mount replaced and the knock went away for about a month, then returned...and has only gotten worse over the winter.

I finally took it to a really good shop called Group 2 Motorsports here in Seattle, and they did a very detailed inspection, test drive and diagnosis and traced it to both front struts! Right side was worse than left, but both were doing it. I contacted Bilstein for warranty help, and they said "no problem, send them in". This is my daily driver, so no go, and asked them to sell me replacements, and credit me when I return the old ones....problem is they do not normally stock the B14 PSS kit for older cars like the E39 540/M5 much anymore....I had to wait two months for them to get back into stock. Well they finally came in and were sent to me this week and installed today. FIXED! No more annoying knock (it was mostly as low speeds).

I will be contacting Bilstein USA for an RMA authorization to return the old ones and get my credit. Labor and alignment is still expensive, as is shipping, but at least it is fixed.

Just an FYI, and wondering if anyone else has experienced this with Bilstein, either their regular sport/HD, as well as the PSS kits?

I have always heard Bilstein are top notch quality, but this has kind of shaken my confidence. I am not a super agressive driver, and the car is not slammed really low either.

I am happy with the Bilstein customer service, just wish they had these in stock and I didn't have to wait so long...otherwise, it all turned out fine. Just hope the new ones don't have a repeat of this issue.
 
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#7 ·
I presently have about 35k miles.
 
#9 ·
PSS coilovers are designed/assembled differently that the stock set up.
 
#8 · (Edited)
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#11 ·
Are you installing the lock washer under the big nut on top of the strut mount?
 
#14 ·
So under warranty replacement, I had new Bilstein PSS B14 front coilovers installed, and the originals returned. Bilstein confirmed the problem (knocking noise) and returned my $624 core deposit.
Now, 13 months and 22,000 miles later, the knocking noise has returned. Only over small, low speed bumps... Will be calling Bilstein tomorrow to start the warranty process over again. What a hassle. Plus I will be out another $500 or so in labor for the installation, alignment and return postage.
 
#18 ·
Actually, the last time around Bilstein wanted me to send the originals back for rebuilding. They only offerred new at my insistence. The problem is they do not stock the PSS, so they had to be ordered, which took a couple months...

Bottoming seems unlikely, as I am not that low. Only about about .5" lower than the stock sport height. Bilstein never disclosed what the problem was, they only confirmed there was a problem, and they would be refunding my "core" deposit on the replacements.
 
#20 ·
How loud is this knocking? Is it unlivable or actually felt not just heard?

I was really considering going with this brand coilovers because of the reputation the struts have for outlasting the car.
 
#23 ·
This is not a new occurence. The previous posters have characterized the sound as a clunking sound. Some have seen corrosion on the strut shaft but how this translates to noise is unknown. I seen this now on Bilstein HDs, Sports and now the PSS. Sad to see the legendary Bilstein quality has gone the way of the dodo bird. :thumbdwn:
 
#24 ·
I'm baffled as well, there is definitely no corrosion on the shafts. I have previously lifted the dust boots while the car is on a lift, and they look fine.

What is also perplexing, is not everyone is experiencing this problem. The reports seen few and far between...I have done a few internet searches and can't find a lot of posts on this issue.
 
#25 ·
What size wheels you running? Anything insanely low profile?
 
#31 ·
Stock, staggered Style 66 17x8 front with 235/45/17 and 17x9 rear with 255/40/17.

Again, the car is not bottoming, the springs are very firm, and I only lowered about 1/2" lower than the oem sport height...not slammed.

The Bilstein B14 PSS is very similar to the PSS9, just with no damping adjustments. The struts have a large nut, where the adjustment knob would be, as they are "pre set", from the factory.
 
#27 ·
I helped NeverSayNever diagnose his clunking issues with HDs. They would go away when he lubed the top nut. Why? Who knows? It would come back eventually. He then tried washers to no avail. He replaced one set of HDs only to have it come back on the second set. No physical evidence of anything wrong. Very strange. I have never heard of this occuring with Bilsteins on any other car model.
 
#28 ·
Fudman, sometime clunk can come from thrust arm. I could of swear my thrust arms were good until I took a 3 LBS dead blow hammer to it from under the car, one side was dead silent the other side was not, the feedback I got from the dead blow was a very miniscule metalic. I then replaced both thrust arms and clunk were gone.
 
#33 · (Edited)
Bilstein customer service called me back today. :) They reviewed my service history and now tell me my previously returned struts were fine (which is not what they told me last go around). They now think it may simply be a issue of "re-greasing the struts". How, or what is involved with that, I have no idea. They said they have the dyno graphs of my returned struts and they are abolutely fine, according to them.

Will need to find out more on what is involved with this greasing process. Apparently it requires disassembly of the strut to perform the proceedure. Not something most shops are capable of doing, I would guess. Bilstien is more than happy to have me ship mine to them for inspection and either rebuilding or regreasing...but says they have no new PSS struts in stock...and unsure when more will be available.
 
#34 ·
Bilstein customer service called me back today. :)
They reviewed my service history and now tell me my previously returned struts were fine (which is not what they told me last go around).
They now think it may simply be a issue of "re-greasing the struts".
How, or what is involved with that, I have no idea.
They said they have the dyno graphs of my returned struts and they are absolutely fine, according to them.

Will need to find out more on what is involved with this greasing process.
Apparently it requires disassemble of the strut to perform the procedure.
Not something most shops are capable of doing, I would guess.
Bilstien is more than happy to have me ship mine to them for inspection and either rebuilding or re-greasing...but says they have no new PSS struts in stock...and unsure when more will be available.
Sounds like a bunch of BS to me...

Is Bilstein expecting every customer to "re-grease" every shock or strut bought from them...?
LOL!
Ridiculous...!
 
#35 ·
Regrease what? Where is there grease in anything but the strut bearing?
 
#36 ·
Not sure, but I assume there might be something inside the strut, such as a "wiper"or something...but why would this be required when no other manufacturer does?

I found my previous email from last year with Bilstein where the customer service rep confirms they found the struts making the noise I described. Not sure why their notes now say something different....
 
#37 ·
Send them a copy of the email and say " wussup u thought i forgots?"
 
#38 ·
Already did. :) But I am NOT holding that against them, they are being extremely helpful and understanding. I just spoke with my installer and they have agreed to allow my car to tie up one of their lifts for a few days so we can send the struts back for inspection and repair. If I overnight them, and Bilstein does likewise, and assuming they can turn them around in 24 hours, this can be accomplished in 4 business days.
 
#40 ·
We've sold a ton of these and haven't seen any problems like this. I even had them on my car for a while until I moved to our coilovers. I still have a couple buddies running the PSS kits with a lot more miles than you're getting out of them.
 
#41 ·
Thanks for the feedback Jared...Bilstein says likewise, that this is unusual. Weird that the problem came back, exactly the same after 22k miles...
 
#43 ·
Interesting Jared, as I am unfamiliar with their numbering system.
I have the invoice from Bilstein from March 2011, and the part numbers for the replacement front struts is: F4-VE3-B127-H2

The original part number on the invoice when I bought the set (front and rear) was:
F4-HE5-B126-H0 But seeing as they superceded part numbers, I have no idea what the actual part numbers that went on my car originally, as I no longer have the box, or the original struts, which were returned last year.
 
#44 · (Edited)
Follow up and possible answer to my problem

My local shop, Group 2 Motorsports removed my PSS struts, with the plan of sending them back to Bilstein for inspection and rebuilding. During the removal, they noticed the top nuts for the upper strut mounts were not fully torqued to spec (I am speaking of the three nuts that secure the mount to the fender). They also noticed after removal, some "witness marks" inside the fender, that showed the upper strut mount (factory oem Sachs/Boge) was moving 3 or so millimeters side to side! Once removed, they went ahead and took them apart to ensure the mounts were still in good condition (they were) and there was no play or issues with the struts (there was not). They put everything together, and retorqued everything to specification, and test drove the car....no more knocking or clunking noises!
So, knowing the original install (about 50k miles ago)was performed by a very qualified technician (master factory Lambo tech) and the current replacements were installed (23k ago) by Group 2 Motorsports, the question becomes: Is it possible for both of them to have incorrectly torqued the upper strut mounts? In the first instance they started knocking around 15k miles, and I replaced at around 22k miles. Then they started knocking again 22k miles later. Have people ever had this problem before? Do I need to start checking these with a torque wrench every 10k or so? Seems a very unusual problem.

BTW, I am glad to know there is nothing apparently wrong with the struts!
 
#45 ·
Very interesting observation. So it sounds like the strut mount was loose against the shock tower and the cause of the noise and not the strut itself. That might explain why when we lubed the strut mount, the clunking would go away. The next question is: Is this an installation error (not likely, given their bona fides)? Or is this somehow attributed to Bilstein characteristics as it appears this issue is unique to Bilsteins ( haven't seen any Sachs or Koni owners report this problem yet)?
 
#46 ·
That is my question as well....what is the root cause? Perhaps the stiffness of Bilstein struts/shocks is transmitting more stress/force or shock/vibration to the upper mount, causing it to come loose? All I know is I want red Loctite applied to those upper strut mount nuts to ensure nothing comes loose again. I'll probably put a torque wrench to them every 7500 miles when I perform an oil change as well.
 
#48 ·
My cousin and I changed my car's front struts with Billys HD's about 2 months ago. I don't remember if any nut other than the top strut nut was a locking nut. Maybe the tech's reused the old nuts?
 
#47 ·
3mm? Some camber kits have less than that. Was there a way to tell if it thru off the aligment?
 
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