Tein coilover failure

[AtomicLabMonkey]

Those of you with Tein's should take a look at this:

http://www.lancerregister.com/showth...5&pagenumber=1

If you're using sticky tires and auto-xing or tracking the car I would put these units on a regular inspection schedule to look for any distortion or cracking in that strut mount. Fatigue failure is a bitch...

[Kevin M]

Oh snap.

[Dean]

Tore right around the butt joint weld which appears to extend to the edges of the tube. Not a great design IMHO. It should have some sort of flange to distribute the load. New design looks much better.

Though the comment about keeping the lock nut locked are interesting. A loose lock nut could cause all sorts of nasty shock load.

[MPREZIV]

I personally visually inspect my suspension every time I've got the wheels off, and check ALL of the lock nuts (height and spring) at every opportunity as well.

I've got to question his "never been curbed" as well, as that seems like an odd failure if everything's installed and maintained as it should be... Although "isolated incident" isn't out of the question as well.

Good on the head's up tho Austin! I'll be sure to check out my shits a little more carefully whenever I have the wheels off now!

[sperry]

Originally Posted by AtomicLabMonkey

Those of you with Tein's should take a look at this:

http://www.lancerregister.com/showth...5&pagenumber=1

If you're using sticky tires and auto-xing or tracking the car I would put these units on a regular inspection schedule to look for any distortion or cracking in that strut mount. Fatigue failure is a bitch...

Good advice for all struts... including the stockers. Also, check your brakes, brake lines, wheels, tires, etc. Pretty much anything that, if it failed at speed, would end badly.

[Nick Koan]

Ever since I started putting more aftermarket parts on, I do the quick visual inspections whenever I'm under the car.

Funny thing is, I didn't think it was as important with stock parts, but it definitely is too.

[tysonK]

Austin surfs evo forums! I knew it!

[AtomicLabMonkey]

Originally Posted by MPREZIV

I've got to question his "never been curbed" as well, as that seems like an odd failure if everything's installed and maintained as it should be...

Weld heat affected zones and thread grooves can be pretty large stress risers. Now I'm not a failure analysis/fracture mechanics expert by any means, just a regular ole' mechanical engineer, but IMO that tubing just visually looks fairly thin to handle both. I think it would have to be some pretty high yield alloy to have been properly designed to handle the loads seen on track with sticky tires.

Fatigue is a funny thing... a part that passes high static or even dynamic stress tests a few times can fail eventually when subjected to a much lower load applied repeatedly for X number of cycles.

[sperry]

Originally Posted by AtomicLabMonkey

Weld heat affected zones and thread grooves can be pretty large stress risers. Now I'm not a failure analysis/fracture mechanics expert by any means, just a regular ole' mechanical engineer, but IMO that tubing just visually looks fairly thin to handle both. I think it would have to be some pretty high yield alloy to have been properly designed to handle the loads seen on track with sticky tires.

Fatigue is a funny thing... a part that passes high static or even dynamic stress tests a few times can fail eventually when subjected to a much lower load applied repeatedly for X number of cycles.

+1

The Tein SuperRace coilovers I have have much heavier duty lower brackets... I was actually surprised at how different they are compared to the Flex's.

That said, this is the first and only Flex failure I've ever heard about... considering how many units are out there, and how many people track/abuse them, I'd be willing to bet this is more of a quality issue rather than a design issue. The Flex's seem to hold up pretty well or we'd hear more stories like this one. But that said, take a look at your bits on a regular basis just to make sure you don't have a "bad" set.

That guy's failure didn't happen instantly. Surely he would have noticed something weeks before the catastrophic failure had he been watching.

[MPREZIV]

Originally Posted by AtomicLabMonkey

Weld heat affected zones and thread grooves can be pretty large stress risers. Now I'm not a failure analysis/fracture mechanics expert by any means, just a regular ole' mechanical engineer, but IMO that tubing just visually looks fairly thin to handle both. I think it would have to be some pretty high yield alloy to have been properly designed to handle the loads seen on track with sticky tires.

Fatigue is a funny thing... a part that passes high static or even dynamic stress tests a few times can fail eventually when subjected to a much lower load applied repeatedly for X number of cycles.

Oh I whole-heartedly agree! I was just pointing out the average person's "I didn't do it" attitude, even when they know damn well what caused the failure. I've seen too many customers with bent suspension parts who claim they have NO IDEA how it got that way, despite the big curb mark on the wheel...

But yes, it's imperative to inspect any parts that take extra load when you're racing, OFTEN. I personally actually go a little overboard when checking my car out, but I've always said anything worth killing is worth over-killing!

[Dean]

I mentioned this at a meet, but will repeat it here. In addition to inspecting everything in the wheel well Struts, brake pads, brake lines, rotors, calipers, hubs, CV boots, etc..., clean and wax your wheels.

Why? To see if there are any cracks anywhere.

It will also make your tire changer happy. And the wax will make it much easier the next time as it will act as a sacrificial layer for the molten brake dust thrown at it at insane speeds.

Wheels do crack, most often at the spoke to outer rim interface. I've never broken one, but probably will some day.