Broken Air Ride spindle

[bret]

At this point it should be fairly well known that I broke the passenger side spindle on the Goodguys Chevelle at the Costa Mesa Goodguys autocross in March. The fact that I did not make a huge deal of this [yet] has raised a few questions that deserve accurate and relevant answers.
This may be a lengthy post so I’ll try to break it down into digestible sections. The main questions seem to be: 1.What caused the spindle to break?
2. What have you done to correct the problem?
3. Should I be concerned about my air ride Technologies / Fatmans spindles?

What caused the spindle to break? The short answer is…I don’t know…yet. While I could offer some informed opinions and guesses, I think it is important to make sure this kind of information is as accurate as possible. While anyone else participating in this discussion is at liberty to offer an opinion [because it is just that…an opinion] I feel that as owner of air ride Technologies, I need to be held to a higher standard of credibility concerning my own products.
The spindle broke at the transition from the inner bearing surface to the larger seal surface. The wheel/rotor/spindle pin/caliper assembly did significant damage to the right front fender, inner fender, and door of the Chevelle. After the wheels left the car we slid about 150 feet on the lower control arm. The wheels assembly rolled slowly across the autocross track, hit the fence and fell over. I was going about 35 mph when this happened. I’ll get some images of the spindle up asap. The damage to my pocketbook was significant…fortunately Grundy Insurance was great to work with and settled promptly.
Here are the facts about the car: 1970 Chevelle – 540 Bill Mitchell engine and a Bowler 4L80 trans. Weight is around 4000 lbs with about 2200 of that on the frontend [I’ll find the weight sheets tomorrow]. The front suspension is our StrongArms with ShockWaves, the taller Fatmans spindles and our MuscleBar swaybar and PosiLinks. We are using a 245/45-18 BFG KD tire on a 18x8 Intro wheel and Wilwood 13” 6 piston brakes.
This car has approx. 7000 driven miles and another 5000 or so in the Goodguys trailer. It has participated in 7 autocrosses so far. Anyone who has seen me drive this can tell you that it gets driven “11/10ths” all the time. We have used up 6 sets of front tires on the car so far.
Here are the facts about the spindle: The Fatmans spindle is a one piece forged steel unit, just like the oem GM Camaro/Chevelle spindles. When I can get the exact material and heat treatment I will publish those as well. The first run of the units were 2.75” taller than oem [ball joint to ball joint] to improve the camber gain characteristics. The steering arm location was moved down slightly to improve the bumpsteer on the Chevelle. It retains oem style brake mounting so any brake system for a Camaro or a Chevelle will fit. Subsequent production runs were revised to a shorter 1.75” dimension over oem height because Fatmans found that some customers were having balljoint bind problems at complete compression if using stock control arms and a “street” alignment. Although this made the camber curve a bit shallower, it is likely more appropriate for street tires and street alignment specs. Brent tells me that these spindles are made offshore. This does not surprise nor concern me…a large majority of suspension components for oem and aftermarket companies originate from Asia and/or India. In my many conversations with engineers from the oem, racing, hotrod, and military sectors, material quality has not been a concern. Design and testing is still done locally, per the customer [as it was with the Fatmans spindle]. The forging house simply makes the component that he is contracted to make.

2. What have you done to correct the problem? I have this particular spindle on my Buick GSX, my 66 Chevelle, my 70 Nova and now on my new 68 Camaro. I have driven these cars over 100,000 miles collectively, and have raced them HARD in numerous autocross and track day events. Because they are raced, these cars are visually inspected on a regular basis in many areas, especially wheel bearings, brakes and spindles. No problem has ever been found. After we broke the spindle on the Goodguys Chevelle I immediately [on Sunday] called Brent VanDerVort, owner of Fatmans. He immediately pulled his remaining inventory and my remaining inventory of spindles and sent them for x ray and hardness testing. All tested good. In the interest of overkill, and because I did have one problem, he sent these units out to have them shot peened and then re-heat treated. At this moment in time [mothers day] I do not have exact data about these tests or procedures. I will gather that information and share it asap.
All of this takes time. As much as we would all like to think that nothing could be more important than our “crises de jour” the hardcore research, engineering, and testing facilities all move at the same slow friggin pace…day in, day out.

3. Should I be concerned about my spindles?
I am not…and here is why.

1. As I stated above, I have used these spindles successfully over thousands of miles on the street and the track. Positive experience breeds comfort.
2. I beat on my cars. A lot. I have also let professional racecar drivers beat on them several times. Hard. If there is anyone who is stressing components more than we are, they hopefully have enough experience to inspect ALL areas of their racecar regularly. This issue has been covered on this website before with good reason. If you race your car you need to inspect it regularly. If you only street drive your car then the inspection frequency rate can go down considerably.
2. With the Chevelle failure, you are talking about a 4000 lb plus car, reasonably sticky BFG KD tires, and an EXTREMELY sticky surface at Costa Mesa. That track was so sticky that my 71 Camaro and Stacey Tuckers 69 Camaro were lifting the inside front tire on the hard corners. Those 2 cars had NEVER done that before. Sticky track = more stress on suspension.

With that said, if you are concerned then by all means take your car apart and look at your spindles. Send them back to me and we will replace, re-inspect, and/or refund your money for these spindles. If you are not comfortable with any portion of your suspension then it is truly worthless. I don’t want my product to be worthless. You need to feel comfortable and safe. My personal email is [email protected]. If you are reading this then you obviously have email…send me a message, I’ll send a call tag to get your spindles picked up and we will discuss how you want to proceed. It doesn’t matter to me if you bought them from Air Ride Technologies, one of our dealers, or the swapmeet…I’ll take care of them.

In addition, I am going to indentify and notify all of my spindle customers about this situation. As was suggested before…they deserve this information so they can have the opportunity to make an informed decision.
I will have a webpage up in a day or 2 with logistical details about returns, exchanges, and /or refunds.


In the meantime I am driving the Velocity Camaro with Henry De Los Santos from Chevy High Performance Magazine to the YearOne Experience in Atlanta this week [if we can keep it running] and will run it hard on the big track and the autocross with my Fatman spindles. I hope to see you there!


The rest of this is personal pontification…feel free to ignore it.

It has been suggested that my products are designed for street rods and therefore not up to rigors of autocrossing, roadcourse, or “pro-tour” use.

I typically don’t expend much energy to refute this…our performance on the track seems to handle that.. My secret is that I never told the car that it was a “street rod”…
Seriously, this is why I get to go to work every day. No challenge= no fun. I like fun. Take a look at our show and autocross schedule and come out to take a look or take a ride. Who knows, maybe you will get to witness more carnage. [I’m sorry that was just mean, wasn’t it?]
The point is that our products are designed for the vehicles that they are to be installed on and for the purpose the vehicle is being built for. You won’t hear us recommending an air over leaf system for a Camaro that is to be track driven. You also won’t hear us recommend a set of double adjustable shocks and a big swaybar for a 50 Merc that is a cruiser. Our main design criteria has always been safety, ride quality, handling performance, and stance…in that order. If you are a former mini-trucker you will remember all the crap we took a few years ago when we spoke out against frame dragging and reverse 4 links. [If you can’t draggit you’re a faggot…you had to love that] You can check the archives of sport truck.com for confirmation.


It has also been suggested that I am not qualified to design and build suspension components because I am not a degreed engineer. Make no mistake…I DO NOT have any degree at all. I never attended college or trade school. I have never made an issue of this, pro or con, because it just didn’t matter to me. However, in the interest of full disclosure it may be appropriate to explain some of my background. [I’ll be brief, really]
Like most of you, I have been building cars since high school. In 1987 I went to work for a rep agency representing MSD, B&M, Autometer, and a few other lines at the NHRA drag races. In 1990 I went to work for Blower Drive Service at the mobile display manager. While there I was involved with the early EFI development with Craig Railsback and John Meaney [he was DFI back then]. Craig and John are perhaps 2 of the most intelligent humans that I have met so far. Craig is who I stole the phrase “If I have to choose between the tape measure and the stopwatch, I’ll take the stopwatch”. John Meaney taught me to not confuse education with intelligence. Again, to clarify, I didn’t help, I learned.
I started Air Ride Technologies in 1996. I’ll skip the boring parts, but at this point I have supplied suspension systems for tens of thousands of customers, hundreds of award and race winning vehicles, dozens of multi-million dollar car projects, several oem concept projects, a handful of NASCAR teams, a few RV and industrial vehicle projects and a couple of high end military projects, one of which involves the V22 Osprey aircraft. Now, I know that it may be unimaginable that any project could possibly involve more money, more planning, and more engineering than a hotrod, but the Marines spend more money on this project every minute than any hotrod project in total I ever even heard about. Our LevelPro controller was required to pass a voltage surge test that cost us [them] $30,000. [Yes, we passed] Our military customer was especially concerned about my lack of engineering credentials until the Marines liaison pointed out that we were able to resolve a suspension issue that had eluded their team of mechanical engineers for several months.
Although I am not a “degreed engineer” I have access to several individuals in several disciplines. I read a lot of books, I ask a lot of questions, and I stayed in a Holiday Inn Express last night. [still paying attention?] I have told many customers that I do not know every way there is to build an air suspension, but I do know several years worth of ways NOT to. [that was supposed to be cute...feel free to insert indignant reply here]

Typically when I talk about Air Ride Technologies I use the term “we”. That is because any significant accomplishment is the result of the efforts of more than one person. I use the term “I” today because I want to project to everyone that I am ultimately responsible for my products, manufactured or vended. I have been known to tell employees “It may not be your fault, but it is your responsibility.” That includes me. Especially me.
I know that I’ll have more info to post in the next few days / weeks. I’m sure that there will be many replies and opinions. I ask that you take what you need and let the rest lay. I will attempt the same.

Bret Voelkel
President
Air Ride Technologies, Inc.

[vp23271]

Bret, Thanks for posting and keeping us in the loop!

I was at the Costa Mesa show and saw the Chevelle running hard! I did not see the spindle failure, but I am very interested to find out what happen. Keep us posted.

[Steve1968LS2]

I too was at the CM GG show.. in fact Bret took me for a ride in the Chevelle about a half hour before the accident.

The first lab he spun it out.. that was fun.. the next lap he didn't even hit a cone, maybe that's because he wasn't driving my car (just kidding Bret).

The point is that he beats the ever loving snot out of any car he is in. Period. My feeling on the spindle is that stuff breaks, even good stuff. That's why race teams, who run the best parts money can buy, bring spares of everything with them to the race.

I think it says a lot that Bret is willing to stand behind his product in this way. Good post.

Hey, I have a pic of the "incident"... want it? Part of the reason it slid so far is that it was using a cone as a skidplate. lol

[class67]

Bret, thanks for the info. I think we all appreciate it, as well as your honesty although, I don't think anybody would ever doubt you or your product (just one of those things, I guess). I saw the car after it happened at my friends shop and was wondering how that could have happened myself?

[MonzaRacer]

Now can ANYONE tell me how Bret Voekel and air ride Technologies aren't the number one top of the line air suspension company/owner?
To me this seals any deal on which suspension I would use.
Oh yeah Bret my 78 C10 is coming up on 4 yrs with ART all the way around and still kicking.

[Bill Howell]

Bret, your honesty and openness on this speaks volumes about your integrity and concern for your customers and products. As you know, I have had Global West/QA1 parts on my goat for about two years/10000 miles. Hopefully, tomorrow we will sit it back down off the rack and for the first time drive it with the new air ride suspension on it. I can not wait. Not only has my car always rode like a tank, I have had countless issues with the shocks. After all the autocrosses I have attended, including RTTHs, there was no real choice for my A-body except air ride after the disappointments with the other products. I for one have no concern at all over one failed part. I know I will never push my car as hard as I have seen that chevelle pushed so many times. I am sure, knowing you, that you will not rest until the answer is found and problem addressed, but meanwhile, I will be driving the goat down to Year One this week, running the hell out of it this weekend and driving it home. See you and the crew there.

[ProdigyCustoms]

Thanks Bret. We sell all air ride products with confidence. I know you will get to the bottom of this and whatever the solution, if any, will be implemented.

[MrQuick]

Automotive parts break all the time. Normal for me to see. I see it daily.

This was a track driven car that was pushed, its expected. I run safety chains and limiter straps just so its not too bad when something does break. It happens. Yes, I do expect it.

Now if this where to happen to a show car that gets your normal sunday cruises after hitting a pot hole on the highway than that would be different.

Get up, brush yourself off and build it better.

[67SSDan]

See... now that's what I'm talking about. The GOOD vendors will step up.

Now... about those camaro pix. We going to have to wait till after next weekend's unveiling to see some full body shots? LOL



Dan

[Bow Tie 67]

quote: " I read a lot of books, I ask a lot of questions, and I stayed in a Holiday Inn Express last night. [still paying attention?] "

Lol

Well written Bret, I'll assume the transition area where the spindle broke was radiused. Looking forward to pics of the broken end that was still attached to the wheel / brake assy.

Matt

[ATAK, Inc.]

I too am interested from a metallurgical standpoint. It breaking at the step from the inner bearing surface to the seal surface sounds like a possible stress riser from the machining process or possibly something to do with the bearing. Of course this is all speculation without seeing close-up pics of the failure. FWIW, I have been working with metals and material inspection for over 24 years. I have a minor in Metallurgy and lots of experience with common and exotic metals and alloys. I am a CWI (Certified Welding Inspector), and a ASNT Level II in the 5 primary methods(Radiography, Ultasonic, Eddy current, Liquid Penetrant and Magnetic Particle Inspection Methods). Please post some close up pics of the failure area of both pieces.

[TonyL]

there's a shot of the broken spindle in this month's PHR. I was surprised to see that the actual shaft of the spindle broke off. When I heard about the failure, I assumed the spindle broke somewhere else.

As for what happened, I'm leaning towards any stock diameter spindle will break under the right amount of load. Fact is, the Chevelle was most likely being driven at that load when it failed. I'm glad Bret is being up front about it. It speaks volumes about ART's integrity.

[HRBS]

Thanks for the informative update Brett and thanks for standing behind your product(s).
But I really want to know how you got Grundy or any other insurance company to cover a "track" incident.

[MrQuick]

I too am interested from a metallurgical standpoint. It breaking at the step from the inner bearing surface to the seal surface sounds like a possible stress riser from the machining process or possibly something to do with the bearing. Of course this is all speculation without seeing close-up pics of the failure. FWIW, I have been working with metals and material inspection for over 24 years. I have a minor in Metallurgy and lots of experience with common and exotic metals and alloys. I am a CWI (Certified Welding Inspector), and a ASNT Level II in the 5 primary methods(Radiography, Ultasonic, Eddy current, Liquid Penetrant and Magnetic Particle Inspection Methods). Please post some close up pics of the failure area of both pieces.

Oh man that was either real bad or very good that you posted that info.....can I have your home phone number and email address....I have some stuff to ask you. LOL
j/k, your wealth of knowledge will come in real handy around here.

Tony, there has been a couple stock failures in that same area hasn't there?

[jlmccuan]

Brett,

I don't know you and don't currently have any of your products in use, but after reading this, I hope to do both soon.

Jim McCuan

[ATAK, Inc.]

Oh man that was either real bad or very good that you posted that info.....can I have your home phone number and email address....I have some stuff to ask you. LOL
j/k, your wealth of knowledge will come in real handy around here.

Tony, there has been a couple stock failures in that same area hasn't there?

More than happy to be of help. I have had way too many interesting things happen to me over the years. Over 20 years ago we had an F-4E Phantom eat a Turkey Vulture at 500kts. Needless to say the engine was not the same. A Major with the incident investigation team called me over to inspect the engine. When I got there the core of the engine sat on a stand with ALL of the blades broken off at least 50%. He asked me to tell him where the cracks started on the blades. I looked at the core for a few minutes and replied, "The cracks started at the leading edge and propagated to the trailing edge". He got a bit hot under the collar, called my boss who came over, I showed him the marks on the blades and he agreed with my findings. I just love titanium.
Sorry for hijacking the thread.

BTW, I had a spindle break off on me several years ago, it appeared to be a fatigue fracture, cyclic stresses on a part like this are enormous.

MrQuick, if you ever need anything, just let me know.
Tom

[TitoJones]

My opinion of the failure has to do with the 1 pc construction and heat treatment of the spindle. I think they are trying to harden the pin by heat treating it, but because it is all 1 pc, it makes the spindle brittle and there fore, prone to failure. If Fatman decided to make it a 2 pc spindle with a press in pin, I think it would extend its life.

Bret- Did you ever run full slicks on the car at some point?

Might want to change the title of the thread too- It's technically Fatman's products that failed, not Air Rides.

Tyler

[Damn True]

More than happy to be of help. I have had way too many interesting things happen to me over the years. Over 20 years ago we had an F-4E Phantom eat a Turkey Vulture at 500kts. Needless to say the engine was not the same. A Major with the incident investigation team called me over to inspect the engine. When I got there the core of the engine sat on a stand with ALL of the blades broken off at least 50%. He asked me to tell him where the cracks started on the blades. I looked at the core for a few minutes and replied, "The cracks started at the leading edge and propagated to the trailing edge". He got a bit hot under the collar, called my boss who came over, I showed him the marks on the blades and he agreed with my findings. I just love titanium.
Sorry for hijacking the thread.

MrQuick, if you ever need anything, just let me know.
Tom

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

[bret]

I didn't have slicks on the car but did run the BFG KD tires that are stickier than the regular KDW's.
Although it is a Fatman spindle, I feel it becomes mine when I sell it to a customer.
Steve Rupp has a general picture of the failure in PHR this month and has agreed to share it with me for this thread. I have a couple pictures myself and will post them after Brent gets his information posted. To post them before accurate information is available would simply invite more speculation. I can say that the spindle pin broke at the base of the inner wheel bearing, it was not at the balljoint mounts. I had heard of another spindle broken a few months ago [not my customer], but heard that the car had been in an accident previously. I cannot verify any of that yet.
I must say that I am impressed by the positive reaction to this situation. I will keep the info coming as quick as I can, no matter how ugly.
Interesting scenario with the jet engine vs. vulture. Carnage evaluation can be fun. [if its not yours, LOL]
To the customers who are waiting on your spindles...Brent has several dozen sets re-inspected, shot peened and re-heat treated. We are getting them load tested before sending them out. Customers with existing units will be covered before new orders are sent out, but with the quantity of his stock all orders whould be covered quite quickly. I know this is not what you all want to hear but is is information you need. This is the first of many thanks for your patience.

Bret Voelkel
President
air ride Technologies, Inc.

[fatiger53]

Fatman here. I offer the following in the interest of providing factual information regarding our G-Force dropped spindle, and the failure experienced by Airride Technologies on their Chevelle for Goodguys Giveaway 2008. We did experience a failure on that car at the Goodguys event in Cost Mesa. The spindle proper, carrying the wheel bearings, separated from the vertical section of the spindle. This car weighs in excess of 4000 lbs, is powered by a strong big block, and was being driven in the Autocross. The spindle should be able to withstand this use, and we took immediate steps to stop further shipments until we could determine the cause of failure. All unsold units were returned to us to allow testing. Once the cause of failure had been determined, we would be able to make a rational decision as to our next step.

I personally designed this spindle with the drop and improved geometry we wanted to provide. I am trained in Mechanical Engineering, and worked in R&D for Textron Corp before founding Fatman Fab. My specialty in college and at Textron was in Failure Analysis. This is a discipline that allows improvement in products by finding the cause of failures, and better design by that knowledge.

The spindles are a one piece forging using 1045 steel with a 91,000 psi tensile strength and a 73,000 psi yield strength. That alloy is commonly used for spindles, axles, crane lift hooks, and other highly stressed components. Based on a 1.25 inner bearing ID, 1.22 square inches are in shear stress, providing a theoretical section strength of 67,000 pounds, using a shear strength factor at 60 % of tensile strength. That is over 15 times the weight of the car, a generous safety factor. After forging, a heat treat and annealing process is used to add toughness/ ductility to the forging with a final hardness of Rc30 being specified. That heat treatment is used to make the part have improved resistance to fatigue from repeated load/unload stress cycles as seen in parts such as these spindles.
Two production runs have been made since 2006, with each marked differently as is normal procedure in casting and forging work. The spindle that failed on the Airride car was from the first batch, marked A0606.

The manufacturer has been engaged in high strength forgings for many years. They produce crane hooks, earthmoving equipment, and automotive suspension parts. In fact, they have been making other spindles and control arm cross shafts for Fatman’s for over 8 years. Thousands of parts have been supplied, with a zero failure rate. This gave us great confidence in their ability to produce this part. It appears that proper design, material selection, and a proven manufacturer were utilized. Yet, a failure occurred.

Once returned to us, we sent the broken part to an independent Metallurgy lab. It was found that a small crack at the root of the inner bearing area was expanded by fatigue load/unload cycles until critical loss of area under stress occurred, causing the failure. The hardness measured Rc18 rather than the Rc30 specified. The bearing surface had been induction hardened (using an electrically heated ring) to a higher hardness in the interest of preventing bearing wear. An improvement in design was suggested by the lab, and another Engineer, by enlarging the radius at the root of the inner bearing area for greater protection from a stress riser at that area.

My conclusions are that the heat treatment was not properly controlled, and further that the localized induction hardening and cooling may have over annealed the material in the critical area. Any material that is soft enough to move under stress can then work harden and crack. After seeing these results, we determined that the first batch had other units whose Rc hardness level was out of spec, while the entire second batch checked out as OK to specs.

We have changed the process to remove the induction hardening of the bearing area, as the Rc30 overall hardness spec will take care of any expected wear. Final inspection has been intensified from the normal industry practice of spot checking, to checking each and every part. The induction hardening has been eliminated to avoid any possibility of over annealing the forged part. A shot peening process has been added to aid in eliminating stress risers, and an increase in the inner bearing root diameter has been added to the machining specifications.

Now comes the really hard part..what to do about the parts already in service, and in stock. The only truly acceptable failure rate is zero. In the real world, with manmade products, failures still occur. That’s not an excuse, but a reality. At this point, based on thousands of spindles and hundreds of this particular design produced by the same foundry, material, and process, and of units installed and used over 8 years, I feel that the failure of the Airride spindle was an aberration, quite possibly aggravated by a pretty extreme use. Again, a user of the spindle should be able to be confident that it can take that usage.

Further, we have scheduled another lab to do a stress test of a stock GM spindle as a baseline, and compare it to an as produced spindle from the first batch, and a spindle from that same first batch that has been re heat treated and shot peened. We will also test a spindle from the second batch, which has had a zero failure rate. As we receive later batches, we shall continue this process of using destructive testing to ensure the integrity of the product.

We will certainly be willing to exchange the spindles from the first batch, marked A0606, for those in the second zero failure batch, for any users who feel this will ease their mind. If they prefer, we will accept returns for refund.

On a personal level, I honestly wish there was a way to absolutely guarantee that any product made or sold by us will never fail. Any responsible manufacturer, builder, or personal hot rodder will feel the same way. The hard truth is that zero defects are an absolute goal, not an absolute reality. When we cannot be perfect, we will be responsible. We will continue to stand behind our products, and to work with our customers to assist in repairing any damage that might occur, as we have for the last 27 years we have been in business.

Thanks for allowing me to provide information regarding this unfortunate occurance. Should anyone wish to discuss this issue in person, please feel free to call me at Fatman Fab, (704) 545-0369, [email protected] or see me at a show.