Broken Air Ride spindle

[derekf]

Images don't seem to come through at work, so that might be it, but I'm not seeing a link, Fatman.

[70bird]

No link here either

[Larry Callahan]

I just uploaded the word doc. Please see the link in his post above.

[bret]

After reading the stress test from Brent at Fatmans I would like to offer the following observations:

• The first production run of spindles, while performing adequately in all but the most extreme environment, suffer the combined issues of a substandard heat treatment process and the lack of an adequate root radius at the base of the spindle pin. The soft heat treatment allowed the spindle pin to bend in extreme use. The continued extreme use [and bending] over a period of time allowed the area to work harden and become brittle. After becoming brittle, the inadequate radius at the base of the spindle pin allowed a crack to form and expand into failure. The absence of either problem would have likely prevented failure, even in extreme use.
• Re-heat treatment and shotpeening of this run of spindles has improved the performance of this unit to the point that the ball joint nut is now the weakest link in this assembly. The failure point of over 20,000lbs is 5x the entire weight of the car. This safety factor is far above most automotive and aircraft standards. The absence of any flex at the spindle pin will avoid the subsequent work hardening, cracking and failure process.
• Future production runs of this spindle will have an upgraded heat treatment and inspection process, as well as an increased radius at the base of the spindle pin to increase performance even more. We will publish the test data for these units when available.

To make everyone feel better, including myself, I am going to get all of these 1st run spindles back for inspection, re-heat treating, shotpeening, or replacement. I have to assume that all of our customers will corner their 4000lb car on sticky tires. Even if they don’t, I want to look at these spindles to see if there are any more unseen problems. I am going to send all of my customers a letter explaining the problem and offering to exchange their spindles or refund their money. This letter should go out at least by the end of this week. I will issue a call tag to get them picked up and when I can track their shipment I will send their replacement spindles. If you have a set of these spindles, please email me [[email protected]] with your contact info. We have several sets that have been inspected, and now tested, to make these exchanges, so your down time should be minimal. Replacements will be fulfilled before new orders are filled. If you know someone who has these units that doesn’t read these forums please forward this info to them. Between this forum and our outgoing letters we should have everyone covered. It is not important to me if you bought them from air ride Technologies, Fatmans, or the swapmeet…we will take care of them.

It ain't fun, for neither me or Fatman, but it is neccessary. We'll get to fun later.

Bret Voelkel
President
air ride Technologies, Inc.

[Steve1968LS2]

Way to stand behind your product Brent and Bret... Many companies wouldn't have done this after one failure and would have chocked it up to "an anomoly".

Sucked that it happened but if this prevents a failure at a more dangerous time (ie, mountain road) then it was actually a blessing in disguise.

Again, kudos for being stand-up guys about this and for disclosing so much information.

[syborg tt]

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.

Being that I'm from the mini-truck crowd and the fact that I am on 5 different mini-truck boards. I heard it over and over "is that truck going to lay frame"? My answer is always the same - Nope.....

Trust me it's a tough crowd, they all want to lay frame. However I am failry certian that there is enough people watching the build of my truck ( over 500,000 views so far ) that they are starting to actually learn that while dragging you frame migh sound cool it not as much fun as driving a safe and reliable vehicle.

With that being said.

When we looked at the suspension for my project mini-truck we didn't have to look any further then air ride Technology.
(the mini-truck if for Kenny )

To date each and every employee that we've had the pleasure to worked with at ART is just like Bret. They are car guy through and through and they went out of there way to help us with this project.

When we were at Good Guys Indy 2007, I finally got to meet Jeremy and he showed me there new Level-Pro system and I was so impressed, that we upgraded to this kit. These guys make great products.

I'm looking forward to working with them on the next project and all future projects.

On a side note my best friend grew up in Jasper, Indiana the home of air ride. He has told me storys about Bret and some of the things that that he's done for people and not only does he run a great company but he is conducts his personal life on the same level.

ps I've never met Bret but i am certain that I will one day an look forward to shaking his hand and telling him "Job well Done".

[ProBell]

Thanks for posting the test data. Here is my question. The test was on pushing the spindle straight up. The 4 stock spindles we found cracked were all cracked on the top side of the pin. Not on the bottom as we expected. Is it possible to put a greater force on the spindle turning the car than straight down in a compression state. When you are turning the car the outside wheel is trying to fold under the car, their for trying to pull the pin down. The cracks we found suggest this is when are spindles saw the most load or flex. For example, I am thinking of a bucket of rocks on a rope. If you spin the rope around over your head it weighs more than just hanging their. I have broke one stock hub and cracked some spindles so I am just trying to think this through. What do you think? Thanks Randy

[Damn True]

Throw in gyroscopic procession and things get really interesting.

[bret]

Thanks for posting the test data. Here is my question. The test was on pushing the spindle straight up. The 4 stock spindles we found cracked were all cracked on the top side of the pin. Not on the bottom as we expected. Is it possible to put a greater force on the spindle turning the car than straight down in a compression state. When you are turning the car the outside wheel is trying to fold under the car, their for trying to pull the pin down. The cracks we found suggest this is when are spindles saw the most load or flex. For example, I am thinking of a bucket of rocks on a rope. If you spin the rope around over your head it weighs more than just hanging their. I have broke one stock hub and cracked some spindles so I am just trying to think this through. What do you think? Thanks Randy

I just want to clarify...you are talking about stock spindles, right? Or at least NOT one of our ridetech/Fatman tall spindles? [insert heart attack here!]

One possibility is that the oem early Camaro/Chevelle spindle/suspension geometry puts the tire in a positive camber position on compression. It is feasible that the force at that point is more lateral on the bottom of the tire than compressive through the tire. That may impose the force in the direction necessary to crack the spindle on the top of the pin. Here is a link to an article on air suspension that has a good side-by-side photo comparison between an OEM spindle and a tall spindle vehicle in a hard corner. Look at the sidewall of the tire in each photo.
http://www.ridetech.com/files_AR/mag...AirtobeDif.pdf

It is an interesting question...I will talk to some people who may have relevant opinions on this. Thanks for the input!

[ProBell]

Thanks for the reply Bret. Yes they were STOCK spindles and hubs not one of yours. My front suspension has been reworked to get the proper geometry and I am running the car at the track on slicks now. The picture is on street tires. Thanks Randy

[68sixspeed]

no stress on it at all... for those not following or aware of the the stock spindle issues for A/F bodies-- https://www.pro-touring.com/forum/sh...ad.php?t=22020

[bret]

Cool car. It makes a big difference getting that tire to lean in instead of out through the corner.
This will give me something to talk about with Gartshore on the Power Tour next week. Thanks!

[hotrdblder]

bret if you look at vinnys pic form the autocross, he has your strong arms in the front with ats spindle and he has no neg camber gain, which would then bring to life what these guys are talking about. maybe some testing on the pin, in that direction should be done?
great way to step up and take some heat, then give back tech data for all of us to take in.
see ya in nashville

[Steve Chryssos]

bret if you look at vinnys pic form the autocross, he has your strong arms in the front with ats spindle and he has no neg camber gain, which would then bring to life what these guys are talking about. maybe some testing on the pin, in that direction should be done?
great way to step up and take some heat, then give back tech data for all of us to take in.
see ya in nashville

Maybe so, but having watched Velocity at Year One, the positive camber issue is is specific to our ATS spindle/Strong Arm combo. Also the broken spindle was on a Chevelle. That doesn't discount the value of testing in the other direction, but if you look at pix of Velocity, the tire is pretty much flat when the car is laid over.