1ST Gen Camaro - Spindle, Hub and Bearing stength, Will they fail [Archive]

David Pozzi

08-27-2006, 10:02 AM

This has been a concern of mine too.
Second gen Camaros have the same bearing package but something like 3/8" wider separation between the bearings, the spindle is pressed into a cast iron knuckle. Corvettes up through 1982 or 3 have the same bearings and spindle diameter with slightly different spacing but within 3/8" or so of a first gen camaro.

With all these Camaros and vettes out vintage racing there should be some reports of spindle breakage if there was a risk. All I've seen myself is one lower balljoint failure on a first gen. The stud shank broke where the threads join the taper. Ive seen a couple of Mustang spindle failures in vintage racing.

One other thing is, I have recieved a couple of emails from guys racing with tall NASCAR type wheels and tires. The extra height of these tires seems to flex the spindle more, and they have experienced brake pad knock back as a result. Still no spindle breakage, but they are probably close to having a failure.

I don't think the wheel bearings are weak but larger bearings would be a nice improvement. You definitely want to carefully check your wheel bearings before running on a racetrack.
David

ProBell

08-27-2006, 01:37 PM

Thanks for the info. This makes me feel better. When you say taller tires do you mean a 15" rim with a slick?
Do you know of a after market spindle and hub I can buy and modify to fit my car? They would have to be based on a stock design.

vintageracer

08-27-2006, 01:59 PM

If you race your car, magnuflux/crack check your spindles and other high stress suspension components every winter as part of your yearly car preperation for the next year's racing season.

Cheap, easy and provides peace of mind. All the Corvette guys running C2 cars upgrade to the C3 spindle since it uses the bigger bearings. I have often wondered about spindles breaking the my GT350. We upgraded it with 70 Mustang drum brake spindles when buildiing the car since they also have bigger bearings. In 9 years of racing and 9 crack checks, I have found no problems with the spindles. I run 6.00-15 Goodyears in the front. These are pretty big tires.

TitoJones

08-27-2006, 03:32 PM

Do you know of a after market spindle and hub I can buy and modify to fit my car? They would have to be based on a stock design.

Randy-

Check out our short AFX spindle. It will bolt in place of a factory one, and it uses much larger wheel bearings via a C5 corvette hub.

Tyler

silver69camaro

08-28-2006, 05:03 AM

Randy-

Check out our short AFX spindle. It will bolt in place of a factory one, and it uses much larger wheel bearings via a C5 corvette hub.

Tyler

Those C5 hubs are pretty good, but the Vette guys wear them out on track duty. A couple of the C5R drivers I've talked to check them about every season. Something to think about.

wendell

08-28-2006, 06:11 AM

Mag you spindles, hubs and axels anually regardless of who sold them to you. I got to see a spindle (fabbed Coleman) failure at Beaverun in July. Lucky the only thing hurt was the drivers wallet.

David Pozzi

08-28-2006, 05:34 PM

Stock Car Products makes a racing spindle that can be adapted to a First Gen Camaro but it requires a Chrysler ball joint on the bottom and a GM pickup upper BJ. They make a steering arm for it but it's got a very long steering arm. The steering arm bolts to the bottom half of the spindle and the arm also has the taper for the lower balljoint in it.

I've been told there is an "Impala" spindle that can be used, but I haven't seen one.
David

Matt@RFR

08-28-2006, 07:07 PM

Mag you spindles, hubs and axels anually regardless of who sold them to you. I got to see a spindle (fabbed Coleman) failure at Beaverun in July. Lucky the only thing hurt was the drivers wallet. Pictures?

wendell

08-29-2006, 05:54 AM

Ha Matt! As you know, a wrecked car at a race track is a sensitive thing. Taking pictures of that stuff is deffinately bad form. I just helped him get it in the hauler as quickly as possible.

Basically is was a pair of stress cracks top and bottom that propogated toward the center. The last 3/8" thick horizontal segemt of the snout snapped clean. Probably took two seasons from the start of the cracking. That was a coleman snout on a fabricated coleman tall spindle.

I think a lot of peole think that parts failures are static events when in reality the part is slowly tearing over time until the final boom. Being proactive and checking out parts, even just vissually, can really help.

p.s.
you and Mark are killing it! Keep it up.

Mean 69

08-29-2006, 06:42 AM

I've ranted on this one in the past, but I am not a big fan of the stock first gen spindles, only to be trumped for my utter disdain for the very early Mustang spindles. Both are really thin, aside for the geometrical dimensions that really limit how far you can go to improve things. On my own car, I still am plagued by flex somewhere in the system, which shows up in brake pad knockback after even moderate turns. I don't know where it's coming from, but I have the worst of all evils in my overall setup to make it an unpleasant experience (manual brakes with lots of piston area up front (Alcon six pots), small-ish bore M/C, rigid mounted (radially) calipers, and relatively large rotors (13 x 1.25", on a Wilwood hat). It forces me to tap the brake pedal to put the pads back out where they need to be, I tap it with the left foot slightly before corner entry, and it works pretty well, but it is very distracting for me, I am a novice driver. You can watch Boris Said doing the same thing on the in-car segments they have of his footwork, but he's a little more experienced than I am....

So, will they break? I haven't heard LOTS (meaning none for me personally) of examples of that, I'm sure there are some that are out there, but this is probably the weakest physical link in the entire suspension setup on the first gen cars. They weren't made to deal with 275 wide super sticky tires, let alone race slicks. If they DO let go, well, I'm sure it won't be a pretty picture, because as Murphy states, if it can go wrong, it will, and at the worst possible time. If you're going to run them, and run them even moderately hard, inspect them regularly, and don't powder coat them!!!! The Mustang track guys routinely magnaflux the early spindles, and routinely find them to be cracked.

And by the way, Wendell's witness of the Coleman spindle failure should be cause for concern, those piece are really, really strong. Really strong. Was he running one of the hollow pin types on that car (i.e. GN hubs), or could you see?
Mark

wendell

08-29-2006, 07:37 AM

I'm supposed to feel bad for Mark because his 13" rotors, radial 6 pucks and 17" slicks are flexing his spindles.

The coleman upright had a solid pin. I got a real good look at it. It was a longterm fatigue sort of thing.

The ride I monkey around with runs GM "penske" spindles. They were magged two years ago. They checked out but will get checked again this winter. Safety first!

BonzoHansen

08-29-2006, 07:54 AM

A few grade A, stupid noob questions: Are most machine shops equipped to magnaflux, or are only specialty shops set up for this? How much does it cost (I’m really thinking in relation to a new part price, not putting a price on safety)? If the part is coated (paint, powder coat or POR15 (regular or the silver with the metal bits), does that hamper the test? How about control arms? Should any other part be inspected?

Sorry if I broke the flow of a good thread.

Mean 69

08-29-2006, 08:24 AM

If the part is coated (paint, powder coat or POR15 (regular or the silver with the metal bits), does that hamper the test? How about control arms? Should any other part be inspected?

EVERY part should be routinely inspected on any performance vehicle. Not many folks with hot street cars like to hear that, but the fact is stuff can and will break, no matter if it is substaqndard to begin with (which virtually always means it WILL fail), or beefcake tough. The spindle that Wendell spoke of with the solid pin is a perfect example, if you help one in your hand, you'd think there is no possible way it could fail other than a serious impact with a wall, in which case everything else would be a write-off too. People think folks are being dramatic when they say it's important to really keep an eye on things, but with the performance our cars are capable of generating these days, too much caution doesn't exist.

Yes, the coatings on any stressed component can and will make inspection far more difficult. I'm not a mag expert, the process is really straightforward and not expensive at all (any engine machine shop will have the goods), but I can say that the parts need to be bare in order for the process to identify stress fractures. Powder coating is on the top of the list of non-ideal coatings for race applications, you just can't remove it to see what's going on, and it is flexible enough to allow the base structure to fatigue/stress fracture, and in many cases hide it. Serious folks will strip all of the coatings (paint, etc) off of the pieces on a prescribed basis and do a complete inspection, then repaint.

I really hate to step on the soap box, but few folks really understand how much work goes into routine maintenance of a typical race car. You don't just load it on to the trailer and hit the track. The scary thing is that most folks that track their street cars probably don't prepare them nearly enough for track days, and that isn't good for anyone. Even with ALL precautions, you simply cannot control all aspects of "everything." If you read all of the disclaimers on race parts stating for off-highway usage, virtually always it is because of covering booty from legal actions if and when bad stuff happens, NOT because the parts aren't capable of performing on the road.

W: I guess I shouldn't bring up the fact that we have year round weather that allows track time while I'm am whining about my spindles, eh? You could be here too! :naughty:

M

silver69camaro

08-29-2006, 08:29 AM

Bonzo,
You bring up a good point.

IMO, a magnaflux job (or dye penetrant, etc) should be done by metallurgical test facility, not a machine shop. Machine shops typically don't have the equipment or know-how to do a COMPLETE test. Not to offend anyone, but you don't see Boeing sending parts to an auto machine shop to be tested. Neither should you, and it really doesn't cost that much at all. You'd be surprised.

Any type of coating or paint can hide cracks & fissures and is why I don't recommend it.

wendell

08-29-2006, 09:31 AM

Look Mean,
It's a well known fact that all the inovative stuff comes out of inclimate weather. In order to progess, you've got to stand in front of your car for ATLEAST three months a year contemplating how to make it go faster. If I lived in socal, the #80 would still be spinning it's wheels (pun intended) and all I'd do is surf, drink cold beer on the beach and chase long legged, tanned, toned, california gir- wait. That doesn't sound half bad. Pick me up at LAX! (someday...)

BonzoHansen

08-29-2006, 12:21 PM

Where does one find a "metallurgical test facility". I'm not sure I'd see that in the Yellow Pages (or would I?)

silver69camaro

08-30-2006, 04:56 AM

Where does one find a "metallurgical test facility". I'm not sure I'd see that in the Yellow Pages (or would I?)

It's in our Yellow Pages under "Metallurgical Testing". If you can't find them, call some machine shops. Many shops have to get random samples tested to meet manufacturer certifications, and use such labs.

David Pozzi

08-30-2006, 09:48 AM

Check with your local aiport repair facility. The FAA has them well under control. They wll do all kinds of paperwork on you and your part before even looking at it. They often have the type of magnaflux machine that magnetizes the part, then tests, then de-magnetizes the part. Crankshafts can be done this way but it's important that engine parts be fully and correctly de-magnetized or metal particles can cling to the part during assembly and cause engine failure.

ProBell

03-27-2008, 05:42 PM

Just wanted to bring this back up to see if anyone heard of anything new. I built my front suspension around stock spindle geometry and would like to find a stong replacement spindle with the same geometry. I would also like to narrow each side by a 1/2" if posible to help with the turning radias with the slicks in a compression state. I broke a hub at the end of last year and now I am concerned about my spindles again. Thanks Randy

David Pozzi

03-27-2008, 07:57 PM

For what it's worth, this same spindle is used on Chevelles with good reliability. A corvette of the 60's and 70's is almost identical in the spindle/bearing area, just 3/16" or so longer. A second gen Camaro uses a slightly longer spindle "pin" aprox 1/2" longer. The same bearings as a first gen.

We have run my wife's car open track and autocross for over 2 years, using the same bearings and Baer aluminum hubs up front. No problems at all. We adjusted them one notch tighter at the most since new.

For my 67 Camaro, I have been looking around for a beefier option for a better margin of safety. Not really anything to report right now...
David

chicane67

03-27-2008, 08:36 PM

I havent personally seen a failure... and have only heard of one or two that did under full blown road racing while I worked for Guldstrand. The typical spindle prep we did negated stress risers. Then again... they were also Zyglow or MAG inspected every year if used in competition.

I have however... actually seen and have read the original spindle blue print from GM. If memory serves me correctly... they will take about 8 tons of force before typical failure. I remember this from when we were doing the AFX spindles... and we were looking for a much greater safety factor knowing that with todays tire compounds and suspension technology... it would need more to meet the engineering guidelines.

Well... the AFX met and exceeded our expectations. It was 12+ tons.

Forged steels fatigue life is about 2 orders of magnitude longer than the cast aluminum and about 1.5 orders of magnitude longer than forged 6061-t6 assuming the same stress amplitude. I can tell you that the AFX spindle was loaded multiple times up to 10 tons with zero plastic deformation.

David Pozzi

03-27-2008, 10:24 PM

Tom,
I was at Laguna Seca and talked to a late model Corvette racer about the spindles he was using. They were billet spindles, not factory stuff. I asked why and he said the originals were too fragile and all the Corvette guys were buying these!
I forget what class it was, but it was quite interesting. It wasn't an SCCA event, more like the Grand Am Rolex series weekend, one of the support race classes.

Olav

03-29-2008, 12:04 AM

Penetrant is a easy way of finding cracks. We use it all the time at work to find fails/cracks at non magnetic parts. (I'm working as mechanichal supervisior at a ship yard)The cost for these 3 spray cans are not high. Anyone can use it.

http://www.grainger.com/Grainger/items/3KU63
http://www.pegasusautoracing.com/ProductDetails.asp?RecId=1207[/url]

Olav

dipren443

03-29-2008, 04:09 AM

Anyone with specific questions on how to perform Magnetic Particle or Penetrant examinations, feel free to IM me. I am an NDT engineer/inspector (about to have my Level III's) for one of the larger power generation companies.

Also, someone asked earlier about Mag seeing through coatings. It will find slightly subsurface defects. There is a way of determining the skin depth and effective depth of penetration for a given inspection.

Zyglo (Just a trademark name), or Penetrant inspection is just a surface inspection and will NOT see through any type of coating. Zyglo specifically refers to Flourescent penetrant, so a black light (not the Spencers variety) is required to perform the inspection. The link Olav posted is for Visible Red Dye penetrant, not as sensitive as the fluorescent variety, but no special equipment is needed.

Like I said, anyone with questions, feel free to ask. I might be persuaded to help anyone local to me out as well. I have access to all of the equipment needed to perform these inspections (Mag particle yokes, black lights, and all the requisite chemicals).

David Pozzi

03-30-2008, 02:01 PM

dipren443

03-30-2008, 03:00 PM

I've been wanting to get a small magnetic particle inspection kit. I already have a dye penetrant kit. I see there are two basc types, a DC and AC/DC. The DC only tends to magnetize the part, which is not a good idea, especially for a crank or rods that could retain metal shavings which would dislodge while running.

Any advice on which to get?
David

David,

You definitely want to go with an AC/DC mag yoke. You will actually inspect the part with DC as this gives you greater depth of penetration. You would use the AC functionality to demagnetize the part. As simple as this seems, after performing the inspection, you basically induce an A/C field into the part and slowly drag the yoke (while still magnetized) away from the part. Be sure whatever kit you purchase has a gauss meter to determine residual field strength after demagnetization. Minimal residual field strength is acceptable. Where have you been looking to purchase the kit from?

Nick

David Pozzi

03-30-2008, 10:16 PM

dipren443

04-01-2008, 04:13 PM

That's what I thought. At first I saw on Ebay a green DC "magniflux" unit, but then read more and it seemed I needed the AC/DC unit.

I found these Parker brand units at the bottom of this page: http://www.tedndt.com/cat/index.php?TED=49

We exclusively use Parker at work. We beat the living tar out of them (all of our work is in the field). They get shipped all over the country and sometimes world. We rarely have any issues with them. Like I said, you definitely want a gauss meter. None of those kits include them.

If you want to increase your sensitivity, a black light will expand your capabilities in both mag and penetrant.

ProBell

04-02-2008, 04:56 PM

Had 3 spindles magnaflux and 2 had cracks in them. I started a post looking for stock spindle measurements.https://www.pro-touring.com/forum/showthread.php?p=378119#post378119 . I hope to send it out to some spindle fab shops and see if they can build me some. Thanks for the help. Randy

David Pozzi

04-02-2008, 09:21 PM

We exclusively use Parker at work. We beat the living tar out of them (all of our work is in the field). They get shipped all over the country and sometimes world. We rarely have any issues with them. Like I said, you definitely want a gauss meter. None of those kits include them.

If you want to increase your sensitivity, a black light will expand your capabilities in both mag and penetrant.

Any idea which model is good? 200? 400?

ProBell,
I have gotten an email from a person using farily tall NASCAR tires and wheels on a Camaro. He had a terrible caliper piston knock back problem. We both figured his spindles were flexing as it was most noticeable after bumpy sections of track.

My 69 race car has the Stock Car Products NASCAR spindle, it's taller by 1.5" or so. The main problem with these spindles is, the rear steer arms are no longer available and they make up the lower half of the spindle including the lower BJ taper.
David

neki67

04-03-2008, 02:23 AM

Lots of info in this thread, BUT good one of you mods please make a correction in the title of the thread. Makes future searching so much easier.

David Pozzi

04-03-2008, 07:22 PM

Thanks, for pointing that out. I normally don't fuss about typos but in a title, it matters when searching.
David

neki67

04-03-2008, 11:51 PM

I normally don't fuss about typos but in a title, it matters when searching.

Me neither (we don't want this to become CC, do we?) but there's too much good info in this thread to get lost b'cause of a typo.

Thanks David,
René

dipren443

04-04-2008, 02:44 AM

Me neither (we don't want this to become CC, do we?) but there's too much good info in this thread to get lost b'cause of a typo.

Thanks David,
René

You know, you would think someone pissed in the wheaties of 90% of the members over at corner carvers... I have spent a bit of time over there (definitely some good info), but just can't stand the attitude of most of the members.

David,

About the mag yokes. This seems backwards, but the 400 is just slightly smaller. It doesn't really matter which one you buy. They are both equally capable. The 200 gives you an 18" span, where the 400 only gives you 12".

Nick

68sixspeed

04-05-2008, 06:57 PM

CarlC

04-05-2008, 07:55 PM

I wonder how good the new aftermarket OE type spindles are?

68sixspeed

04-06-2008, 06:08 AM

Good question, also are they us made vs imported, which steel was used, etc?

I'm just suprised where they are cracking. Granted the seal dia does have a lot smaller radius than the inner bearing step, but I would have thought it would crack at the inner bearing or by one of the ball joints.

MrQuick

04-06-2008, 08:59 AM

Just and update and note of caution for all... Randy (Probell) and I have been thrashing on this spindle situation; 3 of 6 spindles magnafluxed had cracks; 2 of the cracked spindles have never seen track use. They all had cracks that showed up on the largest dia of the pin where the inner seal rides.

I think 40 year old parts are starting to show their age and weak spots, lets face it years of pot holes and who knows what can cause a lot of shock load which may be more of the cause of the cracks.

Time to start looking at alternatives, ATS, fabricated, possibly even billet cnc's steel ones... Dan Great points Dan, im sure everyone out there building these cars always assume a big hunk of metal will out last the car but if they are showing in them spots,it might not be the case. Thats a real bad spot.
When ever I build a Chevy with stock spec components I will always run the ATS F/X spindle. Its light, strong, reliable at a reliable price. ATS the brand the pro's choose.

Thanks to you guys for finding out that these flaws exist.

68sixspeed

04-11-2008, 03:00 PM

Thanks Vince... I had 2 more magnafluxed this week, the ones on my '68 with the 13" brake setup, one was cracked. Small cracks, but still not good; that's 4 out of 8 spindles. Billet or ATS are going to be in my near future...

F and A body guys too-- MAGANAFLUX YOUR SPINDLES!!! -Dan

David Pozzi

04-12-2008, 09:46 PM

I had my 67 spindles done, 140,000 miles on them and the car was autocrossed hard with 10" wide wheels and slicks for the last 40K miles.

I was warned at an event to be sure to mag them and the guy said he'd seen a lot of them that were cracked. I heard the spindles from Master Power Brake were US made and pretty good quality. Tuftriding of them is supposed to help, - don't know much about it though.

I have a pair of 1968 (might be 69-70) Olds Delta88 spindles, they look almost like the Camaro spindles but larger, they are taller and the steering arm holes are wider apart.
You wouldn't want to use the whole assy with stock brakes, the cast iron hub and rotor are HEAVY!!!
https://static1.pt-content.com/images/pt/2008/04/olds_cam_spindles-1.jpg https://static1.pt-content.com/images/pt/2008/04/olds_cam_spindles_sides-1.jpg

I've seen several early mustang spindles break at the track, one resulted in a roll-over!
David

CarlC

04-12-2008, 10:33 PM

David,

Were any cracks found in your '67 spindles?

David Pozzi

04-13-2008, 11:46 AM

No, Mine were fine, - Go Figure!
David

So the cracks were found near the seal area, not the backside of the bearing? - Interesting...

CarlC

04-13-2008, 03:05 PM

RRRRR! Wonderful. One more thing to check.

Did the parts arrive?

68sixspeed

04-13-2008, 05:12 PM

Maybe it's just our northern pot-hole roads! Seriously, it might have something to do with salt... any rust on the seal surface is a stress riser point. Combined with the small radius on the machined seal area, it explains part of it; One part that did suprise me, they tend to be on the upper 1/2 of the pin, the compression side. I would have expected on the bottom or tension side. I'll upload some pics Monday. -Dan

David Pozzi

04-13-2008, 08:32 PM

RRRRR! Wonderful. One more thing to check.

Did the parts arrive?

Carl,
Yes got them, thanks.
I just ordered the Parker DA-200 kit with black light.
Carl, wanna send me some spindles to check? :cheers:
It would probably cost more to send them up and back than to just have them done locally, but if you are going by my place soon, drop them off and I'll do them for ya.
David

68sixspeed

04-14-2008, 01:43 PM

Here's a picture on two of them; basically they all were in the same area, 10-2 o'clock on the pin, on the seal dia. Nothing you would spot without magnafluxing.

https://static1.pt-content.com/images/pt/2008/04/P4140017aJPG-1.jpg

pdq67

05-14-2008, 04:19 PM

David,

They are loaded in compression, so I really wouldn't worry about it, imho, b/c a crack can't propagate in compression.

Probell,

You can use drum hubs to to narrow your track about 9/16" per side if you hold stock rim front spacing vs 2-piece and 1-piece cast rotor/hubs.

David P's great site shows this if you want to go over to view it.

And I looked into making a taller forged 1st gen. spindle but got put off b/c of the cost of the forging dies when ordered in 500 piece lots.

Something like $50,000 for dies alone if I remember right b/c it's being several years ago..

And I have the spec's of the grade of Ductile Iron that is used to make cast spindles saved at work.

pdq67

David Pozzi

06-21-2008, 11:19 PM

Paul,
My hub comparison is between a two piece disc hub and a drum brake hub. I believe there is no offset difference between the two piece assy and one piece.
David

ATAK, Inc.

06-22-2008, 09:16 AM

If anyone is interested in doing thier own testing, I would be more than happy to help. I have been doing Non-destructive testing since 1984, 14 years with the Air Force , working on all the cool fighters. There are a few things to know about the different tests;
1. Magnetic Particle Inspection, part needs to be clean but ANY relatively thin coating does NOT matter, MPI can detect sub-surface defects.
a. Using a portable yoke, orientation of the yoke is critical, you must magnetize in at least 2 orientations.
b. You can de-magnetize with a portable yoke, and a must have is a gauss meter.
c. You can over-magnetize a part, giving false indications.

2. Liquid Penetrant Inspection; Part must be totally clean, including any coating, best for non-ferrous metals.

This could go on and on, it took 4 months just to learn the theory and physics behind the 5 areas of testing, and Spectroscopic Oil Analysis. If anyone wants further knowledge, you can PM me.
Or, if anyone is really interested, I could start a tutorial thread about the subject. Actually, I advise that anyone planning to do this themselves to contact me prior to testing, it is very easy to to mis-interprit an indication, it is even easier to miss an indication.

David Pozzi

06-22-2008, 10:08 AM

ATAK, Inc.

06-22-2008, 11:16 AM

I've been looking for a good book or website to learn how to use my new MPI yoke.
I read that you should practice on a known bad part and not use the highest power settings as it won't reveal small cracks like lower power settings would. I was quite surprised that the kit didn't come with any instructions at all!

I still need to buy a gauss meter, they sell several but the more accurate "calibrated" versions are much more expensive, than non-calibrated. I purchased the AC/DC yoke, supposedly setting it on AC will demagnetize.
David

Hi David,
The ASNT volume on Mag. testing is over 1,000 pages... way to much to cover in instructions.:) :look:
You don't need an expensive gauss meter, an inexpensive one will do, it is best used for indicating an over magnetized condition and if it is de-magnetized. When testing something with different cross-sectional thickness, like a spindle, you need to induce the field perpendicular to the orientation of suspect defects. next, you need to start with the smallest section and make sure your field, on the gauss meter, is between 4-8. If you put too much current into the part you will get magnetic "writing", that will look like a defect. Then inspect the part from smallest to largest sections. To de-magnetize, simply put the probe on the part the same as when you magnetized, induce the field and slowly pull the yoke away from the part to a distance of 3' or so.

What kind of inspection media are you using? Visible is the least sensitive but you get into more expence of needing a UV light with the more sensitive products.

Either using a known bad part or making one by drilling a real small hole so it is barely sub-surface will work. The great thing about mag particle is it will pick up sub-surface defects.

CurtiSS 69

06-24-2008, 11:15 PM

I modified my front suspension using stock spindles,hubs and bearings. I have been to the track a few times on street tires with no problems, but am planning to use track tires next year.
The car works quite well "better than the driver" and I am getting nerves that one of the stock components might fail under the hard cornering or extended runs at high speed.
Please let me know if anyone has ever experienced part failure.
Thanks for your help Randy.

Hello Randy,

I have had a problem in the area you indicated in your original post. This was a problem with the bearing-hub assembly. I track my 1st generation Camaro quite a bit -I've done 7 track days so far this year- and I have encountered a problem area that showed up when going from a 400 treadwear tire to a 220 treadwear tire (which I did this season). I lost a hub, as a the inner wheel bearing was over loaded and the outer race spun taking the hub out. I suspect that was from additional pressure was put on the bearing due large amounts of negative camber that is required to get the tire tread to lay flat for maximum tread patch during very hard cornering. I drove the car to and from Buttonwillow in my track alignment configuration, and on the street too work, and to the beach (i.e. about 500 miles). I heard a noise that was getting progressively louder and found the right front wheel was very loose. It was strange as the car drove well due to large amounts of positive caster, so I didn't feel it going down the road. Needless to say I will be changing alignment at the track now and changing it back to a street configuration for the way home.

One other thing you may be interested in is that when you make a big change in tire grip -and you are able too push it- you will need to change your old setup quite a bit to take advantage of the new grip levels. You may need harder springs, stiffer antiroll bars, adjustable shocks, extreme alignment, etc..... Beware as the car may become uncomfortable and "twitchy" on the street after these modifications. My personal experience is to get everything adjustable if you can, so you can dial it in for future changes. It depends on what you want: a track toy with a license plate, or a street car that you can enjoy at the track. I trying to setup a street car that can be tracked, but some modifications have crossed my comfort threshold.

About the spindles I bet you could use the ring test as a quick way to crack test them, as they are forged. I used too use this method many times for forged crankshafts (i.e. if it rings it is good and if it goes thud damage the bearing surfaces with a hammer so no one saves it). If you are really worried your spindles, hubs, and bearings you could run stock car components, but this is up to you.

I'm glad too know you are out there enjoying your car on the track. Speed comes with schooling, experience, and confidence, or at least this is what I was told. I'm not too fast either, as my cornering is good but my braking sucks. Everyone has something to improve on. Good luck Randy.

Regards

CurtiSS 69

ProBell

06-26-2008, 06:35 PM

Thanks for the info CurtiSS 69. Post some pictures of your car on your PT garage. I would love to see them. I have tried numerous times to contact the tech department at Stock Car Products with no luck. They keep telling me I need to speak to (Tony) ? When I try to talk to him he is either busy or not their. I have left my number numerous time with no call back. Me and Dan (68 Six Speed) are working on getting all the factory specks on the original spindles so we can try and cross them over to something we can use or have some custom ones built.
Some food for thought for you on your hub failure. I run 3.25 deg of negative camber on my car all the time. The car has 12000 mile on it with this setup with no bearing failure. The hub that failed on my car actually split from the inner bearing to the flange. Thanks again Randy

David Pozzi

06-26-2008, 06:49 PM

SCP used to make a rear steer spindle, I have them on our 69 Camaro. The lower balljoint hole and steering arm are one piece, and that bolts to the upper portion of the spindle which has the spindle pin.

I believe they discontinued the lower portion rear-steer version and only sell the front steer type.
David

ATAK, Inc.

06-27-2008, 09:48 AM

About the spindles I bet you could use the ring test as a quick way to crack test them, as they are forged. I used too use this method many times for forged crankshafts (i.e. if it rings it is good and if it goes thud damage the bearing surfaces with a hammer so no one saves it). If you are really worried your spindles, hubs, and bearings you could run stock car components, but this is up to you.

The "ring" test will work in some applications, but with a part that will typically have a fatigue crack (from cyclic loading) which can be only several microns wide, less than a mm deep, if even over 20mm long still makes up only a small fraction of the cross-section, not enough to dampen sound propagation, i.e. "ringing". Stress cracks will be even smaller, that is until a shearing load is introduced. It is neat to do failure analysis on broken parts, I even had a small hand in inspecting the Challenger main landing gear.

CurtiSS 69

06-30-2008, 06:22 PM

The hub that failed on my car actually split from the inner bearing to the flange. Thanks again Randy

Randy,

We have something here...you have had a hub failure as well. Maybe this is the weak point. The spindle may not be the "high" risk item unless others chime in on their spindle failures. I wonder if a better hub is available, or will it be a machining and polishing process too minimize the stress risers to improve it?

As far as my car goes it is stock with Addco antiroll bars, C4 Corvette brakes, Moog front springs, and Moog rubber bushings. It still has a 350 and a Qjet too. You would not be impressed at all.

Regards

CurtiSS 69

68sixspeed

06-30-2008, 06:42 PM

it's not just the hubs, not to say they are not weak, but I've found a 50% spindle failure on magnafluxing spindles that did not have hub failure, even just saw normal street use. I'm still waiting for my aircraft place analysis on the spindle I sent out, but it's likely a forging issue. What I'd be curious to find out is who forged them in the 60's, and how many dies they used? Usually they would be tooled in pairs as a minimum, which could explain a 50% problem if the flow was not right on one side of the forging die. Lots of variables on this one, best bet is to magnaflux every spindle and keep inspecting; or change to ATS, aftermarket, fab'd, etc.

It hit me, well my car while driving back from Carlisle, the shock the car took on some of the pot holes and bridge expansion joints is likely as bad as any shock load the spindle sees on the track. Sustained load is going to be higher on the track, but as far as starting the crack, street conditions can provide plenty of reason.

paul67

08-30-2008, 01:41 PM

Here's a thought , in the olds days the wheel and tyre's were a smaller dia ,but the main thing is the tyre height ie profile height , early tyre's were 60 70 and higher and what people are using now 35,-50, I would have thought that the early tyre would take out a lot of pot hole etc bangs from the hub ,instead of the later low profile tyres, i mean some profiles are that low you can crack a rim. Is this a poss common denomiator ?.

68sixspeed

08-30-2008, 07:36 PM

Interesting though, and I'm sure our modern low profile and wider tires are harder on the spindles, but I have found 2 cracked spindles off unrestored cars, one was a 6 cyl 69 camaro I have that still had it's 14" rims on it.

-DA

12-05-2009, 05:47 PM

If anyone is interested in learning about Non-Destructive Testing and Evaluation here is a link:

http://www.ndt-ed.org/EducationResources/CommunityCollege/communitycollege.htm

It's got excellent, in depth info on the major NDE methods from the physics behind it to practiced methods and techniques.

-DA

onseytote

08-01-2010, 01:27 PM

The "ring" test will work in some applications, ...

What is a 'ring test' ?

Sleeper68

10-25-2020, 07:35 PM

What is a 'ring test' ?

Hit the part lightly with a hammer when suspended on string/wire etc. If the part "rings" brightly and loudly, it is a good indication there are no cracks. If the audible sound is dull, it islikely there are cracks in the part. This is a common test to perform on crankshafts. It is not the most scientific but it is better than nothing.

Sleeper68

03-14-2022, 05:11 AM

To resurrect this thread from the dead...will they fail? Absolutely. I just had two failures last weekend. Check out the pictures

Basically is was a pair of stress cracks top and bottom that propogated toward the center. The last 3/8" thick horizontal segment of the snout snapped clean. Probably took two seasons from the start of the cracking. That was a coleman snout on a fabricated coleman tall spindle.

I think a lot of people think that parts failures are static events when in reality the part is slowly tearing over time until the final boom. Being proactive and checking out parts, even just visually, can really help.

This is exactly how my driver side spindle failed...and how my passenger spindle would have ultimately failed. A crack formed, then propagated over time. Eventually a second crack formed on the other side of the shaft and both cracks propagated towards the center until a fast fracture occurred when the spindle was heavily loaded while autocrossing. I had a lower control arm fail in a similar way as well. All are fatigue failures. Spindles are very heavily loaded components so I urge all to check their spindles regularly. I checked mine this past October but either missed the cracks or they weren't there then. Scary stuff. I am very fortunate for these failures to have occurred in a controlled environment and resulted in no harm to anyone.

It appears the upper crack on the failed spindle was there for awhile (hence the discolored beach marks). The lower crack must have formed later, but since the area is well greased, it could have been there for awhile before corroding. Interestingly, the passenger spindle also had a crack, but has not failed yet. This crack is pictured and is on the bottom of the spindle shaft. To be clear, I did not Magnaflux or MPI the spindles in October, I merely performed a visual inspection. Both cracks formed in the fillet where the 0.750" OD shaft blends with the tapered region of the spindle shaft.

stab6902

03-14-2022, 08:38 AM

To resurrect this thread from the dead...will they fail? Absolutely. I just had two failures last weekend. Check out the pictures

Great information, thank you for sharing. I'm assuming these are factory GM parts, not reproductions? Might also be helpful to add tire info and roughly how much abuse they took before breaking (i.e. 5 years of 10 autocrosses a year or whatever) for context.

Sleeper68

03-14-2022, 09:59 AM

Great information, thank you for sharing. I'm assuming these are factory GM parts, not reproductions? Might also be helpful to add tire info and roughly how much abuse they took before breaking (i.e. 5 years of 10 autocrosses a year or whatever) for context.

These are reproductions, purchased from SSBC in 2011. The spindles have about 25k miles on them. Autocrossed for the last 7 years w/ average of 8-10 events per year. 2015-2019 on 200tw 245/45R17 tires of various brands. 2020-present on 275/35R18 200 tw tires. Plenty of mountain runs throughout the years as well.

It is my suspicion that the spindles cracked late last year sometime, but I have no way of knowing for sure.

I actually designed a spindle to replace the GM short spindle in the summer of 2020 which uses a Coleman "Grand National" spindle pin. Spindle shaft diameters are 1.625" inner and 1.000" outer. I have yet to finish the project but this failure is certainly going to expedite the project.