Had a catastrophic failure this weekend at VIR. If not for JCrist's HUGE help in loaning us a JRZ shock, we would not have been able to race at all.
The TCK shock failed where the upper bolt goes through. I contacted TCK and they said this type of failure is normally due to the bolt being loose and they have seen it before. Stranger things have happened and the bolt may have been loose, but we nut/bolt checked just a couple races ago.
Anyhow, upon inspecting this portion of the shock and comparing to the JRZ, it is apparent that the JRZ is just built WAY tougher. Not sure if ASTs or Motons are the same way, but the JRZ portion that is the same spot as the broken part of the TCK was prolly 3 times thicker (maybe more).
Koni wont warranty it, TC wont replace or give us a discount, so just a note to those running TCK coilovers to check those bolts after each event. Prolly would be even better maybe to weld in some reinforcement washers. Sucks to have to do that on such an expensive piece, but it is what it is.
Last edited by magnetic1; 10-10-2011 at 11:07 PM.
Sucks to hear about the failure - I have only ever seen a problem with that when the bolt comes loose, as TCK told you. I have seen TCK, AST, and a few other, cheaper brands with this failure.
Edit: Tq spec on all 3 bolts is 80 ft lbs. I know the lower 2 come liberally coated in threadlocker, I think that upper one does too? Or is it just a locking nut?
Last edited by fsmtnbiker; 10-10-2011 at 07:41 PM.
Chris
97 M3
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Glad I could help but the true credit goes to James at BimmerWorld. He provided me the spares and they are meant to be available to BW customers at the track in cast of such emergencies. Wonger may have TCK Konis but he is a champion BW customer.
In regards to the strut, 3 times is an understatement. The Koni appeared to be stamped thin metal. The JRZ is two thick pieces of steel welded to the strut body. IMO it would shear the bolt rather than break.
whatchu got
thats an expensive part to fail like that, regardless of why. sorry to hear it.
What are you doing with them now? I'll buy em off you...
But seriously my fabricator can (and has) fixed that exact failure before, also on a Koni. It is a problem, but it can be reinforced.
-Luke
EFFEKTIV Motorsport #189 GTS2 - Ground Control / Motorsport Hardware / Hawk Brakes
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That's too bad. That whole suspension is a typical BMW "barely strong enough" design. Compare it to a Subaru front strut and you'll know what I mean. It was just a couple weeks ago that someone reported this same failure with a set of AST's.
On my KW's, the flanges are fairly thick stainless steel.
When's the last time you had an off? With sheet metal that thin, I don't think it would take much impact to start that tearing loose from the strut.
Im going to probably buy one shock to replace and then sell. If you are really serious, PM me. Problem with fixing this particular strut is that because of that failure, the bottom portion that mounts with the 2 bolts is bent.
Conrad, like others have posted, this seems to be on the Koni and ASTs. The JRZ is WAY more stout. I'll take a picture when I remove the JCrist/Bimmerworld spare. (Thanks BW!). Last time there was an off... hrm. Prolly MidOhio a few months back. I'll examine the other side tomorrow and report back.
Last edited by magnetic1; 10-10-2011 at 07:57 PM.
Dang this kind of makes me have second thoughts about using the TC Klines I have ready to bolt in for next years track season!
Is this failure common on heavily tracked or raced cars with the TC Klines?
I have actually heard of this happening to a Bilstien PSS9 front strut too.
I've seen this happen several times also, the loads need to be distributed. Skip welding a specially designed bracket is a common design solution.
Last edited by Hellabad; 10-10-2011 at 08:58 PM. Reason: 99
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-Luke
EFFEKTIV Motorsport #189 GTS2 - Ground Control / Motorsport Hardware / Hawk Brakes
Visit us @ https://www.facebook.com/EffektivMotorsport
That nut in your pic doesn't look like its going anywhere. Its a nylock and threaded all the way onto the shaft.
I refuse to believe it just "backed off" some.
Thats BS to me.
Looking at the photos of the Koni vs the JRZ and Advance Design, no comparison.
Very inferior upper bolt bracket on the Koni.
Not something I'll likely ever see (being an E30 guy for life),,, but good to know when people / students ask for recommendations.
Good post, sorry to hear of the failure though, and them not standing behind the product.
jimmy p.
88 E30 M3 Zinnoberot - street
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Agreed. Icing on the cake is they want $500 for a new shock. $200 to revalve it. All based on a "poor design". I didnt want to go too far in expressing my opinion in the off chance they would somehow come through (though Lee from Koni hasnt emailed me back yet) but it doesnt even look like that will happen. At least if AST fails, they will try to work with you to give you stuff at cost or covered labor.
Here is a better picture to really show the difference in the design and how thin that metal really is. So I guess in the end, yes, the bolt may have backed out. Maybe user error, etc etc. But if you are going to track a car, you better be checking those bolts after every weekend or you will suffer a similar fate. If racing, you better check it after each session.
I wont publically bash a company because that just isnt me, but if someone asks me about suspension, you better darn well believe that I will tell them exactly what happened to mine and explain how the "competition" has a much beefier design. They can make their own decisions based on that.
Last edited by magnetic1; 10-10-2011 at 11:10 PM.
Eric,
Was it the drivers or passenger side. I had a bolt come loose on mine back in 2009 and fall out and it bent the bottom mounts.(talk about positive camber !!) Was still able to get a bolt back in the upper and run it for the rest of the weekend. Just had to make some camber adjustments to compensate. Anyway I have a good passenger side Koni if you need it.
-Scott B.
You sure it didn't fail because you use too much curbing whilst racing? That's a no-no you know...at least according to some damper dealers around here...
Mine happened at Gingerman, so less speed. Luckily I slowly drove it back to the pits and got it fixed. For the record, mine didn't tear, the bolt came loose and fell out !! If you can possibly trade a right side for a left, you can have my good one. Just let me know.
-Scott B.
This looks just like my KW's. I'll try to get a pic tomorrow and post it. I'm not claiming KW's are in the same class as the JRZ's. Just that the construction is similiar. It's uncannily similar. Like they rolled off the same production line.
Yeah, KW's don't have that...he JRZs have swaybar mounts on both sides of the shock so you can swap them around.
Crap, I've never looked at those bolts. Thanks for the heads up!
"Fear disturbs your concentration" -Sabine Schmit
1995 BMW M3/2/5-- S54 + Mk60 DSC, California Smog Legal (Build Thread)
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Wow I have TC Kline coilovers..looks like i should be keeping an eye out and checking torque more often.
No matter what suspension brand you have, I REALLY hope that it is in everyone's check list to check those bolts after every event. No matter race weekend, or HPDE. It is what you should do and this is not a TC Kline or any other suspension companies fault, it is what you need to do.
There are many out there with TCK suspension that doesn't have this failure, and it doesn't do justice to them to give bad grade on a such a successful product.
Bottom line, shit happens, and it comes down to how frequent it happens, and if you consider all of TCK customers, I am sure that's preeeeety low in percentage.
Last edited by Evice; 10-10-2011 at 11:50 PM.
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Wow, thanks for this thread. I've got a set that has seen a lifetime of well and proper "use"... No issues after 7, maybe 8 years, but I'll be keeping a much keener eye on them from now on.
[Ethan "if it weren't for that cone" Connor|323is #89DSP]
80 ft/lbs. sounds really low for a bolt that does that much work. with slicks, you can pick up half the car from there. it is possible the bolt was tight, but not tight enough to hold still once slicks got hot. i helped troubleshoot a similar thing on a spec miata. i have never experienced it before. a control arm bolt was clunking after two laps. the bolt was tight enough for cold tires, but once a bit of heat came in, the bolt would shift.
combine that with the fact that the metal is thin to begin with, and multiple assembly/disassembly cycles could make the metal thinner. it really doesn't look to be up the the task of full race duty. it's a reason i still track with street tires. sympathy for the metals.
David Ortiz
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