Technical Checking for tire cord failure

Hey guys. Earlier this year I had a Coker whitewall blowout on me coming back from Viva Las Vegas. The tires were only about 2 years old with a ton of tread left on them. It appeared that the cords broke within the tire causing it to fail from the inside out. Needless to say it was a fun ride getting pulled over. Coker replaced the tire under warranty but since then I've had a nagging vibration at freeway speeds that my butt dyno is telling me is getting worse to the point that I've pretty much parked the car until I can figure out what the issue is. The U-joints are in phase and nothing else has changed other than the one tire which initially failed. The tread depth between the new and other tires are less than 1/16". So now I'm wondering if the other tire may be ready to fail as well. Is there any way you guys can think of checking this before I get under the car again to check it all out?

I plan on going over all the culprits that I can think of which include taking the tires to my local shop to recheck balance and watch the tires for runout and possibly a bent rim. Recheck my pinion and transmission angles even though I've done it before. Check the rear shackle bushings and shocks for wear. When the tire blew it shook the shit out of the wagon to say the least so there's a chance this old girl got something knocked out of whack.

As always, thanks for all the help. NAES

 

I'd check and compare the date codes on all the tires. Might give you a clue as to if they were all part of a bad run of materials or manufacturing.

 

Find a tire place that can do 'road force' balancing. Rather than simply spinning them up the machine places a point loading on the tire surface as if it were running on the road. Other hambers have done this to find their otherwise good looking tires were breaking down internally. I think road force might be tm Hunter.
Chris

 

Put wheels on that are known to be good. Does the car run right? Put one Coker on and test again. If good, put one more Coker on, test again until you find the bad one

 

Jack the car up and watch the tread as you spin the tire (or drive behind it). Look for the tread zig zaging or anything unusual in one spot. Also look at the tread as you slowly spin it, look for bubbles or spots that the tread is thinner then the rest. I just changed a tire at work with just one lug sticking up higher then the rest, caught my eye when I was walking by. It was a used truck we bought with retreads.

Examples of easy to spot tread separation.

 

Call Coker tell them what you told us maybe they will replace the other three.

 

I've had many issues with out of round non concentric tires from Coker.
I drove my '33 from Boston to Bonneville with Cokers firestones, anything over 70 mph resulted in a warp speed vibration.
I know thair radials are ok but I don't run them.

I actually search swap meets for good original tires now.

 

OK guys thanks for the input. I actually did send a similar message to Coker but am waiting to hear back. I'll do a thorough tire inspection and rotate the tires until I hopefully find one that's causing issues for me.

Hopefully I'll have some news one way or another to report back. NAES

 

One thing that we did in the tire industry was to perform "autopsies" on failed tires, to determine if there was a continuing pattern requiring an engineering/manufacturing change, or the failure was caused by outside influences, like impacts, low inflation, overload, penetrations, etc.
There are definite identifying, determining signatures for almost every failure. The "blow out" is the end result of a series of events. The fact that Coker warranting one tire may be for customer satisfaction, or a manufacturing defect; only they know.
I would swap out two tires at a time for two known, good loaner tires, see if there is a difference, and narrow down to one culprit. Tread and body ply separations can occur from a multitude of causes. Finding them before they become a failure is the challenge. Unfortunately, most manufacturers will not warranty a tire UNTIL it fails, so you need to be more informed than their dealer is, and show them the preceeding cause. GOOD LUCK!

 

wife's '50 Chevy pu had a "good" Goodyear fail inside. was on the freeway, and all of a sudden heard a thumping noise. stopped off freeway and looked at tires, with no visible problem. got going again and same problem. once on another off ramp saw no problem but, had to be one. called for flatbed tow home. while winching truck could see that one front tire had a flat spot. kind of looked like one of those single tire display racks where you can not see lower part of tire.