Broken Air Ride spindle

[ATAK, Inc.]

My hat's off to you, that is integrity. I currently do not have any of your products but would not hesitate to buy anything.
In regards to the Vulture vs F-4E, I have many stories of interesting events with the USAF, but better told in the appropriate forum.
Once again Bret, a big to you and your company.

[WEAVER]

Your a class act,nice to know there are people who make parts that are tested the way yours are,Sometimes parts break that is why race teams take a whole bunch of spares.I'm still buying your products.We work on a lot of cars that have air ride installed and say they will buy again.

[406 Q-ship]

Bret; Let me say this up front I'm not a fan of air bags for a handling type of car, with that said I commend you on your honesty and forthrightness. There are few companies today that would come out and say that they had a problem with their own vehicle and what has been found up to date, you deserve a big applause for this action. If any of you are in the market for this type of suspension system this is the man and company to talk too, he is honest ( a rare commodity in todays market).

Returning to the failure, what about the bearing inner race where it contacts the spindle, could you have a point where the sharp edge of the inner race caused a stress riser? This might be more of a cycle life issue over a catastrophic failure with how the race rides on the spindle spud. If the heat treat on the inner race were harder than the heat treat of the spud then the race under load or movement could displace metal giving you the dereaded stress riser. Just a thought.

[Boulder69]

Hey, you could have told him that the cracks started when the 60lb raptor entered the engine inlet.

Turkey vultures aren't technically raptors and a big one weighs in around 6 pounds. Still really big birds when they fly into engines.

Back to the regularly scheduled program....

[Gordz32]

Well Said Bret! I must say that you guys continue to impress me everytime I talk to someone from the company or recieve more products. Your products are top notch, and your customer service is quite possibly the best I've ever experienced.

[Larry Callahan]

Above you will find posts from a couple of threads I merged into one. I am sorry but a few might be out of order. I have not been able to figure out how to move an individual post inside a thread.

Also, there were a few of the first posts from the new air ride Camaro thread I moved to the link below. I just can't figure out how to put them all together in one long thread in order.

https://www.pro-touring.com/forum/sh...ad.php?t=43264

[bret]

Returning to the failure, what about the bearing inner race where it contacts the spindle, could you have a point where the sharp edge of the inner race caused a stress riser? This might be more of a cycle life issue over a catastrophic failure with how the race rides on the spindle spud. If the heat treat on the inner race were harder than the heat treat of the spud then the race under load or movement could displace metal giving you the dereaded stress riser. Just a thought.

These kinds of possibilities are why I say that I simply do not know at this point. This is a very plausible scenario, and one that I immediately gravitated towards because it would have indicated a true anomoly...a freak, if you will. But I saw no indication of any abnormality with the bearing or race.
Not only am I impressed and humbled by the overall support we have gotton about this, I am impressed with the quality of thought and analisys directed towards this problem. As with most difficult problems, I think we will find a stack of small problems that have added up to failure. More later.

[CarlC]

But I saw no indication of any abnormality with the bearing or race.

There will be no indication of insufficient cornerform radius on the bearing rings. The only time it MIGHT show up on the rings is if the cornerform was too big and did not allow them to properly seat against the spindle shoulder.

Do you have an Rmin and Rmax specified for the cornerform radius? Unless both are specified it is left up to the manufacturer to what this Rmin value will be. Given that it is easier to use a simple turning tool with a small-radius cutting face vs. a true Rmax tool, often the manufacturer without having the specification or an inspection process to verify proper sizing is left to do what is the cheapest.

The Rmin value must be chosen by the design engineer to maximize strength within the confines of manufacturing capability. However, cornerform radii is an easy thing to do vs. keeping superprecision tolerances.

Since it was not mentioned in the other posts my concern would be that there may be spindles with an insufficient cornerform radius. Even if the spindle was properly heat treated the possibility of catastrophic failure significantly increases when a high stress-riser is introduced. Crack initiation and propagation can quickly follow even in low-load and low-cyclic conditions.

I can't tell you how many shafts I've seen, and had the displeasure to inform the customer, that this type of situation could have been easily avoided.

[slowcamaro]

I can't tell you how many shafts I've seen, and had the displeasure to inform the customer, that this type of situation could have been easily avoided.

QOTY? Sig material for sure...

[newbaa]

lol.

That is very impressive. Especially the fact that you are willing to replace ones that somebody might have bought second-hand. That's somebody who's willing to stand behind their product... Someone who want's to know they are producing the best damn product out there and they're proud of it.

It's a long ways off, but when the time comes, you better believe i will be running air ride Technologies stuff on my '70 Chevelle.

[AccuAir]

Way to go Bret and Brent! As a relatively young manufacturer in the industry (29), you guys have set a very valuable example on how to properly handle a "delicate" situation like this. You have also set a precedent toward providing higher quality products through real world punishment in front of everyone (even the magazine editors =). I think that if every aftermarket manufacturer were to publicly punish their products and display it for the world to see, the results would be ugly. Infact, if the big 3 auto manufacturers made their failures as public as you guys do, we may all be riding bicycles right now.

Having an ME degree, I was immediately thirsty for details when I heard of the failure. I was impressed to read this thread and see Brent providing some real failure analysis backed by real numbers. I think that anyone who owns these spindles should feel better knowing that this wasn't a random manufacturing defect that could pop up on some percentage of parts. This was a general design/manufacturing issue that has been 100% resolved.

On a general note, a 63 year old friend of mine has one of the nicest '32 Roadsters on the planet (if you're into that kinda thing =) He built the car himself and made a permanent compartment in the trunk with mounting provisions for spare parts (distributor, carb parts, hand tools etc). Obviosly, he has been left on the side of the road by each of these parts at some point in his life. I would like to think that we are creating a new era for aftermarket parts, where reliability is paramount. Forums like these with threads like these make me think that we are headed in the right direction.

[6'9"Witha69]

I can't tell you how many shafts I've seen, and had the displeasure to inform the customer, that this type of situation could have been easily avoided.

I can't believe you actually wrote that!

[Damn True]

These kinds of possibilities are why I say that I simply do not know at this point. This is a very plausible scenario, and one that I immediately gravitated towards because it would have indicated a true anomoly...a freak, if you will. But I saw no indication of any abnormality with the bearing or race.
Not only am I impressed and humbled by the overall support we have gotton about this, I am impressed with the quality of thought and analisys directed towards this problem. As with most difficult problems, I think we will find a stack of small problems that have added up to failure. More later.

Just out of curiosity, is this your first and only spindle failure?

How about Fatman spindles not sold through ART?

[CarlC]

Yeah yeah yeah, yuck it up.... My industry has way too many innuendos.

[EeeDeeEye]

How refreshing to see this type of response from a vendor/manufacturer! The first time any product fails, it is an "incident" and normally discounted or ignored. Afterwards, additional failures of the same nature should be considered a "trend" and examined immediately... but often continue to be discounted or ignored. The fact that Bret and ART pulled all stock from the shelf after just an "incident" speaks volumes about the individual and the company! They chose to take the path in which common sense and public safety win out over the almighty dollar... quite remarkable in this day & age.

I don't own any ART products, but I was considering using them in my project. After reading this thread and ART's response, I would have no qualms about using any of their products. Thank you for reminding me that there are still companies that desire to build quality products AND stand behind their products during success and failure!

BTW, sorry for the lengthy first post!

[darren@ridetech]

Just out of curiosity, is this your first and only spindle failure?

How about Fatman spindles not sold through ART?

I do know for a fact that this is the only spindle that we have had fail. I'm not sure if Fatman's has had any.

[bret]

Hello all! While I have been away from the office for the debut of the Velocity Camaro at Road Atlanta this past weekend, We have made at least some progress of the spindle issue. Brent has a stress test scheduled for this thursday May 22 to test 4 spindles. We will test a first production run part [from the lot where the failed spindle came from], a second run part [where there were no heat treat problems], a first production run part that has been re-heat treated and shotpeened, and a stock spindle. I do not yet have the technical parametes of the actual test. We will have those details and pictures of the test after completion. More info to come.
As far as other broken spindles, I do not know of any other broken parts. If there is anyone who has a broken spindle, or even knows about a broken spindle, PLEASE let me know [bret@ridetech.com] I do not care if it came from me, Fatman, or the swapmeet...I need to have this information. If you are squeamish about posting publicly, just send me a personal email.
As a side note...I took Velocity to the Year One event at Road Atlanta this weekend and run several 26.6-26.9 autocross times on BFG KDW tires [stock 08 Vettes were running 27.0's]. I also ran the big track at over 125mph.[fun squared, BTW] Then I drove the car 400 miles home [mostly in the rain], all on the second run of a Fatman spindle. We will inspect that spindle [as well as the rest of the car] this week for any problems.
Check out ridetech.com for more Velocity info. Thanks!

[LONE*STAR]

I have to raise my hand in the class, to confess to coming from the Minitruckin crowd and I remember actually saying that, and I remember as layin frame became popular people didn't want ART comp. But you sir with these street challenge kits have changed a hole lot of people's opinion on what exactly a Air suspension equip vehicle is capable of....wait....Let me restate that a ART equipped vehicle is capable on the street, track...or any where else.

I will do a street challenge kit on my next build.

[JEFFTATE]

I'm here to testify that the Velocity Camaro looked good on the track !
No broken parts !

[fatiger53]

Fatman here. We did do an independent tensile test of the GForce spindle, and have written the report based on that. As it is too large to post directly here, please go to the following to see the entire report. And thanks for a place to expose problems, as well the solutions!