Claims of "defective" tires causing "Blowouts" continue to be posted on YouTube

 Here is a post from, July 22, 2012. The owners of this Airstream continue to use the word "defect" but also fail to identify the defect. I also see no signs of them running a TPMS.

"Blowout" A Real Life Experience

In the previous post, I covered Run Low Flex Failure, RLOF, and how there were telltale signs or physical evidence that while each taken individually are just circumstantial in nature but when taking as a whole make a very strong case for the tire having been operated for a number of miles at very significant air loss. In this post, I want to walk you through the thought process of a forensic analysis of the evidence that is available and show how an opinion or conclusion is reached.

First I need to tell you that I have not had the opportunity to personally inspect the subject tire, but there is a YouTube video and I will show you some shots from the video and tell you what I see in these shots. Second I cannot tell you about the individual as I have had only limited correspondence about this tire failure but according to statements in the video they called it a "Blowout", said they had checked the air pressure in the morning and had only driven about 45 miles before the loss of air occurred.

So lets see what the pictures show. I have highlighted the area of interest in each picture. In pic #112 we see in the yellow area signs that the interior of the tire was worn from abrasion on the inside of the tire under one side of the tread rubbing on the inside of the tire above the wheel. This occurs at 0 psi but takes more than the half mile it takes to come to a stop to wear this much. Also the tire must still be in one piece such that the tread can uniformly contact the lower interior of the tire so the wear occurred before the tread part of this tire broke away. In the red area we can see a few dark holes where the body cord has melted and shrunk back into the tire structure. This occurs when the body cord exceeds 390°F. To put this temp in perspective properly loaded and inflated tires may get to 160°F and ultra high speed tires such as seen at the Indianapolis 500 may see 200° to 210° but rubber starts to come apart an just a little more than that.


In pic 108 is another view of the same location of melted body cord. If the cord had simply failed due to high pressure the cord would be frayed. Also note the nice circumferential line the failure took. More on that later.


 Moving on to picture 057 note the areas circled in red. An alternate view is seen at the arrow in pic 426. Now if we compare the loss of the ridge that is easily seen in pic 121. What this means is that the upper sidewall was in contact with the road surface for a number of miles and the outer edge of the sidewall "Scuff Guard" raised rib has been completely worn down. What we do not see is the lettering of the "Scuff Guard" worn away so we know that the wear was not due to the trailer being repeatedly parked against a curb.


+++++++++++++++++++++++++++++

Now I am sure some are wondering how I can tell the difference between running a tire at 5 psi vs 0 psi. Well here are some shots from an experiment I ran myself a few years ago.


  This first picture here on the left shows the wear of the upper sidewall that occurred in only 3.9 mi while the tire had a minimum of 5 psi cold inflation. This is a bit like the wear on the RV tire sidewall

The next picture is of the interior of the same tire. You can see the nice circumferential crease/crack that has formed. This tire did not generate enough heat to melt the body cord as I was driving at less than 10 mph for the 3.9 mile test. That crease is at the location up the sidewall similar to where we see the circumferential failure in the "Blowout". Note there is no contact between the inside of the tread and the inside of the tire above the wheel as seen in the RV tire.

If you look at some of the examples shown in the previous post you will note that many show the same nice circumferential failure line.

Here are some examples that I use as ref pictures to help me understand the Root Cause of a tire failure.

Here are pictures of melted body cord, broken body cord and the holes sometimes left when the cord heats up and shrinks as it melts.
I hope this helps you see how easy it is to be mistaken when you think the failure is because of a defective tire when in fact the evidence shows the tire lost air, the Rv continued down the road at normal highway speed and after a few miles the tire "blew out". The only way to have some warning and to protect yourself against this all too often type of failure is to have a TPMS which will warn you as soon as the tire loses 10% of its air.


Bottom Line: I do not think this tire was "possibly defective" or a "crap tire". It did not "fall apart for no apparent reason". It came apart because it lost its air and the operator did not know till too late.  

 

##RVT976

The tire was "Defective"

Originally Posted by tap4154

They are now defective tires and should be replaced under warranty. Heck, maybe the dealer even knew they were defective? Do not let the dealer or Goodyear get away with not replacing them for free. BTW that the dealer even suggested putting the defective tires on the back tells me they may be shady...

I suggest you look up the definition of "Defect".
A belt separation in a condition that has a cause. The cause may be a defect such as some contamination was built into the tire between the belts or the wrong rubber compound was used on a batch of tires, as I discovered when inspecting tires back in 2000. As I pointed out in THIS post there are also external usage factors that can contribute to the initiation of a belt separation.
If you worked in a coal mine and after 30 years were diagnosed with "Black Lung" would that simply mean your body was defective which would make the condition your parent's fault?

If you had a sidewall flex failure due to running with only 20% of the air pressure required to support the load is that an indication of the tire being "Defective". You can learn more about this condition by reviewing THIS post in 2011 on Sidewall "Blowouts".

Simply claiming a tire is "defective" is the go-to excuse used by many that have no working knowledge of or don't want to spend the time investigation the "Why" tires develop various conditions.

If you have a tire failure and even if you don't know why it failed. Even after reviewing the posts on this blog that identify various reasons for a tire to fail, I still suggest you file a complaint with NHTSA. Please however just describe the condition of the tire and be sure to include the vehicle VIN and the full tire DOT serial.

When to file a complaint with NHTSA

I have previously strongly suggested that when people have a tire failure they need to file a complaint with NHTSA.

Got this question "Thanks, Tireman. My next question is when is it appropriate to report to the NHTSA? After any flat? Or are there specific indicators?"


Excellent question as we don't need to be "crying wolf"

If we start at the end of the process I think it will help us understand when and why we would want to contribute to the database of tire failures.

I think we can sum up the primary objective for NHTSA as to decrease the number and severity of injury or accident costs due to a failure of an automotive system or component. One way to achieve that goal would be to hold the manufacturer responsible for providing parts that deliver reliable service for normal and expected operating conditions.

One way to hold a manufacturer accountable and maybe "hold their feet to the fire" is to order and require a manufacturer to replace a part that has been found to have an abnormally high failure rate due to either design or manufacturing problems.

Based on data submitted to NHTSA, that agency decides if an investigation should be started. The investigation could be limited to a review of test and manufacturing data or it could involve NHTSA conducting it's own tests.

So what data does NHTSA use to decide it an investigation is justified? There is suppose to be a combination of warranty data from the part manufacturer plus a review of complaints filed by individuals.

This presents a problem for NHTSA. How should they judge consumer complaints when they know that consumers seldom have the technical knowledge to do a proper or thorough evaluation of a product failure?

So the question really is.... Should the tire manufacturer be held responsible for a tire loosing air due to puncture or leaking valve? It may be difficult or nearly impossible for the consumer to do the proper investigation to learn the root cause of the failure.
It is well documented that over half of RVs on the road have one or more tire in an overload and or under inflated condition. Should the tire company be held accountable for an overload or low inflation?

Bottom Line
If you believe the RV company or the tire manufacturer should be held responsible for the tire failure then you probably should file a complaint.
If you take a few minutes you might even decide the failure was not the fault of the tire company but of the RV company that selected a tire with no margin for any loss of air or load variation.
  You still need to provide tire information but in the last case of poor tire selection I would be sure to include statement with actual measured loads and the small reserve load the tire selected provided.

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"Why do so many RV tires seem to be failing?"

 Well, that may seem to be a reasonable question but in my opinion it is based on what is often inaccurate failure analysis. In reality, tires fail for a relatively small number of Root Cause reasons that can be discovered, but it does require detailed and sometimes exhaustive investigation. By "Root Cause," I mean the initiating feature or condition that eventually led to the failure. Too often people confuse the tire's ending condition with the initiating or "Root Cause" reason for the tire to end up in the condition they are observing.

For the last few years of my 40-year career as a tire engineer, my primary job duty was to investigate failed tires that had conditions that were hard to understand or provided confusing and sometimes contradictory evidence as to the Root Cause for their condition. With that background, I have developed some guiding principles for the most likely reasons for tires to fail.

These are, in no special order:
1. External Damage. These include punctures, cuts, impacts, wheel and valve failures and similar conditions.
2. Run Low Flex Failure. This is best described by the failure of the tire sidewall due to excessive flexing. The flexing is the result of operation when the tire is significantly under-inflated.
3. Belt & Tread Separations. This is when the belts of a radial tire detach from the body or from each other and/or when the tread rubber detaches from the top belt.
4. Manufacturing Defect. For the purpose of this discussion this would be when components of a tire were not manufactured to intended specification.

The "Why" for some of these are obvious, such as the External Damage category.
Others can be further traced to various contributory reasons.

Run Low Flex Failure This is a more accurate description of what some incorrectly call "Blowout". When a tire looses significant inflation air they flex much more that the body cord can tolerate. Excess heat is generated which can, in extreme cases, result in the Polyester actually melting. I showed examples of what this can look link in THIS post. Polyester is used in most Passenger, ST type and LT type tires. Steel body tires are used on most Class-A RVs, the steel can fatigue. I covered "Zipper" failures and steel fatigue in THIS post.

Belt & Tread Separations occur primarily because the rubber around the belt cords or between the belt rubber and the tread rubber isn't strong enough. Now it can be weak for a variety of reasons. Some might be design, some might be manufacturing and some weakening can be caused by cumulative improper service conditions.

Now let's talk about tires made by a reputable company, i.e., one that has tire stores and dealers with physical stores and sells tires that have a warranty of two or more years.
If this tire is subjected to thousands of miles of lower inflation or higher loading or operation at higher speeds or stored is full sunlight it is reasonable to expect the strength of the belt & tread area rubber to loose a good portion of its strength primarily due to the increased operating temperature of the tire. If this tire is in service on a tandem axle trailer then there is also increased Interply Shear which can overload the belt area rubber. The combination of the above may result in a belt or tread separation.

Another possibility is a Manufacturing Defect. These usually occur in small numbers as tires are built in batches so the substitution of the wrong type of rubber may cause tires to fail. It is important to understand that in almost all cases this type of "defect" usually shows up at early life of the tire. It is also very important to understand that unlike some lawyers, engineers deal in facts and logic. Simply having a tire fail is not in it self proof of a defect but all to often that is the position that those in the legal profession seem to jump to. That approach may result in a nice payout to the lawyer but will not result in product improvement as there has been no determination or identification of the actual initiating "defect".

Finally there is the possibility of a design weakness. Now I do not believe that anyone is intentionally designing tires to fail but this sometimes may occur when the performance goals of the manufacturer are limited to meet the bare minimum for strength and durability and the focus is primarily on low cost. There is no absolute way to identify these tires but I do believe there are indicators when looking for tires that are made to a higher standard of quality and durability.
I would consider a tire company reputable if it had a chain of stores across the country. If the tires carry the name of the manufacturer and have a multi-year warranty the longer the better then they probably have higher durability requirements than those established by DOT.

 For ST type tires I would look for tires with a Speed Symbol of "L" (75 mph) or faster. Now a side point about speed. I did a POST a little while ago on the topic and strongly recommend you read it. I do not think I would recommend any tire for general use that does not have a speed rating molded on the sidewall.

I do hope this post will help some to have a better understanding of what can contribute to tire failure and consider what you can do to lower the chances of having such a failure.

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Tire Bulge. Defect? or Damage

Sidewall bulges can be difficult to diagnose. Sometimes it is even possible to misinterpret a depression as a bulge so lets start off today's lesson with clarifying the words.

According to Dictionary.com  bulge means a "rounded projection, bend, or protruding part; protuberance; hump".  I think we can all agree that this is a sidewall bulge.





A depression would be the opposite, or "sunken place or part; an area lower than the surrounding surface". Sometimes I may use the terms "Bulge in" and "bulge out"just to be sure people have a clear understanding.
Look closely at this shot and I think you can see that this is a depression in the sidewall.

 Here are a couple of other shots showing sidewall depressions.






OK So now you are probably asking why are these two conditions in tires and are they defects or what? Lets step back for a moment and consider how tires are made.







The basics apply to all tires, be they small 10" or 12" as seen on micro cars or 22.5 or even large mining tires like this one.






In this post there are some links with videos showing the basic process of wrapping layers of fabric (or sometimes steel cord) that is in a sheet of rubber, around a drum. The place where the builder starts and stops has a "splice". Now the goal is to have a strong enough joint to keep the uncured rubber together till the tire is cured. In some constructions this means a small overlap of one to maybe 4 cords. If the overlap is larger than desired there is a doubling-up of the cord and this is what creates the depression. I know this is counter-intuitive but you need to remember that when a tire is inflated the rubber stretches and the textile cords stretch a slight bit. However if the splice is "heavy" or larger than desired the forces from inflation are resisted by twice the normal amount of cord and rubber so the stretch is less than in the rest of the tire. There is nothing wrong here other than a visual depression.

Now a bulge is just the opposite. If the splice is "open" or there are cords missing then that area will stretch out more as there is only sidewall rubber resisting the air pressure so the sidewall stretches out just like a balloon. A bulge from an open splice is noticeable as soon as the tire is inflated. If you see this on a new tire point it out to the tire dealer right away and confirm the bulge is below the level of concern for that make of tire. This will probably be less than a tenth inch above the surface of the rest of the tire and less than 1/2" wide. If larger I would request a different tire unless the dealer is willing to put in writing that the tire is safe.  Get a nice close picture of the tire for your records and be sure the bulge does not get any larger.

The other thing that can cause a bulge is broken body cord from some sort of impact such as a curb, pothole or from hitting something on the road. Here are a couple shots of a 22.5 that suffered an impact.

.One thing to point out how I know this was not a factory defect. I have yellow arrows pointing to the small amount to irregular tread wear. You will note that this level of wear is fairly uniform around the tire. If the defect had been in the tire from when new I would expect the sidewall bulge to affect the tread wear. Since it didn't, that indicates to me the break of the body cord is recent.

In case you are wondering what broken cord might look like here are a couple shots of broken Polyester cord from a smaller tire.

.I hope everyone now understands the difference between a cosmetic depression and a bulge due to a tire impact.


If you have a Bulge that looks anything like the examples above I would not drive on the tire. If we are talking about a high pressure tire (75 psi or higher) I would not even stand near the tire while waiting for service. A tire explosion can be damaging or even injure people.



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What is the Best Trailer Tire?

I frequently get asked "What is the Best tire for my trailer?

I don't want another blowout"

My answer:

 I previously did a post on "Best Tire".


Sorry there is not enough data to provide a more focused answer.  I am sure some are hoping I would provide the one size and one brand that will solve all their tire problems.
I would point everyone back to this link from an RV forum with data from NHTSA. As you can see the numbers of RV owners that make the minimal effort to file a complaint sends the message to NHTSA that there are no significant problems with RV tires. I also know from looking at some of the complaints the quality of the information is spotty even if a complaint was filed.

Examples include wrong size, wrong tire brand, missing or incomplete DOT serial. Expecting information on actual load, speed etc is unrealistic and expecting an accurate description of the real failure is just a dream.

Engineers react to and work with facts. I have been trying to educate a few folks on another forum that melted body ply cord, as seen in tires with a Run Low Flex Failure


is physical evidence of a tire having been run under-inflated at highway speed. The discussion ended with one poster accusing me of hiding the facts and lying to keep my job. Of course he had no idea why the body cord melted but was certain I didn't know either. That ended my participation on that thread.

I know of no data to indicate that anyone is intentionally making "bad" tires. I do know of data that confirms the majority of RVs have tires in overload and that a significant percentage of tires on the highway are under-inflated. I share with others the  personal observations that a good number of trailers are exceeding the speed limit of their tires.

Multi-axle trailers place unique and high side loading on tires. This cause internal forces that contribute to the short life for tires in this application. This is a fact based on engineering and all tires are subjected to this type of structural load. It is just a fact that multi axle trailers are worse than single axle RVs.

Bottom Line
If you want to minimize the probability of having a tire failure on your multi-axle trailer, all I can suggest is you read my post on "Best tire", inflate your tires to the sidewall inflation 100% of the time, at least once confirm your side to side and axle to axle unbalance is not giving you an overloaded tire, use TPMS w/metal valve stems and do a free spin inspection at least once a year.

 and cover your tires with WHITE cover whenever parked in the sun for more than a day. You will probably still only get 4-5 years out of your tires because of the internal stress load but hopefully they will be 5 years with no problems.


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The tire was "Defective"

I see this statement or somethnig similar in many posts on various RV forums. The problem I have is that too often the person making the statement offers evidence to back up their claim.

 The mere fact that a tire failed, simply does not mean it was defective. If someone wants to make that claim they need to provide a plausable theory on which material componenet was made incorrectly or which part of the tire manufacturing process was done incorrectly in such a manner that it would result in a tire failing in that specific manner.

Most radial tires made today have about 20 to 25 different components.

 This Wikipedia page identifies nine major components

 Watch this video and you will see a manual process used for a farm tire.
 
Hankook has a nice graphic showing more steps in detail for radial tires
 
Here is a promotional video from Michelin. The part about automatic tire assembly is very similar to what you would see in just about any modern tire manufacturing plant making Passenger, Light Truck or TBR Truck/Bus-Radials .
 
You can see that from manual to fully automatic the steps are very similar. It doesn't make any difference who makes the tire as all tires share very similar construction features.
So now that you have a little better idea of how tires are manufactured Try this exercise. Identify a step in the process that could be done incorrectly on one tire or a small group of tires. The out of tolerance step or material needs to be close enough to spec to allow the tire to finish the manufacturing process and to also allow the tire to function properly for a few hundred or thousand miles but then this error must somehow cause the tire to suddinly cause the tire to come apart but first provide no warning and second leave no evidence of the out of spec part or material being present in the failed tire.

I think you will find that it is very difficult to have a material out of spec enough to function acceptable for a short time but then to catistrophically fail a few miles later and to also leave no physical evidence.

I am not trying to imply that mistakes are never made but since the manufacturing process makes tires and even the components in batches if a mistake is made it should affect all the tires in that batch which would be from a couple hundred to a few thousand. If in fact those defective tires somehow managet to pass through final inspection unnoticed and make it to the tire store where they are mounted on your RV I think you can see that in all likelyhood all the tires with the same defect would fail in identical manner.
If a group of tires fail and if dealers or owners report the fialures to NHTSA then there is a high probability that action would result.

There have been a few cases recently where thousands of tires were recalled because a small number had been found with a defect. What I haven't seen or heard about is a recall because a single tire failed.

When we see a single tire fail and it leaves evidence such as worn sidewall or melted polyester body cord

or fatigued steel body cord as seen on the right.

Tire engineers can be quite certain the failure was not caused by a manufacturing error but in fact the tire was operated under-inflated at highway speed for a few miles. Also when a tire has managed to perform satisfactorily for thousands of miles before failing it is again very unlikely because of a manufacturing error.

All to often those that jump to the conclusion that the tire must have been defective because they checked the air a few hours of days before the tire failed. These folk fail to realize that tires can fail with sidewall "blowout" in less than 5 miles of running at significant under-inflation.

Here is an example of a tire that had been run under-inflated in a controlled test of 3.9 miles at only 10 to 15 mph. You can clearly see the internal damage.

This tire still had 20% of the inflation needed to carry the load so it was not completely flat. That circumferential line is where the body cord would melt or fatique if the car had been driven at highway speeds and only a mile or two further. However dollars to donuts most people would say that since they had checked the air 100 miles prior to the failure the tire must be defective.

Quick post on "BLOWOUTS"

Lets think about our favorite topic for a few moments.

Some people believe that tire blowouts happen for no apparent reason. Others are convinced that even with TPMS you will not get any warning before there is a catastrophic failure. Well while watching a re-run of the TV show Mythbusters the other day, I saw a perfect example of just how difficult it is to simply make a properly loaded & inflated tire blow out.

For those that haven't seen the show, you should know that the "hosts" are two special effects experts who really enjoy blowing things up or creating some other dramatic footage for TV or movies. In this particular episode, which originally aired June 6 , 2007, they set out to make a truck tire explode and hit a dummy to confirm or bust the myth that exploding truck tires can kill.

Just one minor problem... They could not make the tire blow out. They designed a rig that would allow them to run a lightly loaded truck tire at highway speed. First they shot the spinning tire with a .12 gauge shotgun using a large deer slug. They hit the sidewall of the spinning tire as intended but they got a "pissss" of leaking air but no explosion.

Next they cut most of the sidewall into the steel body ply then using an industrial torpedo heater they raised the temperature of the tire. They also lowered the pressure to only 30 psi. Still no sudden failure. After watching the test I noted that they were supporting the truck tire with a heavy fork lift so the sidewall was not deflecting as would happen in a real world condition of only 30 psi while fully loaded.

You can see the large red heater in this shot. The dummy was their test subject that they originally wanted to hit when the tire blew out. Note the lack of sidewall deflection. This was why the Mythbusters failed to achieve their goal of having the tire explode.

  
This set of conditions also was not enough, so after bursting the sidewall by over pressurizing the tire they again spun it up and finally were able to make the tire, that was already severely damaged, come apart.
  
Here you can see the results of all their efforts.

but you can still see that the truck was suspended so the tire was not flexing as it would in real life.

Bottom Line  Even when intenionally damaged this video shows how difficult it is to fail or blowout a tire if you do not have the sidewall fold and flex as it would when run extremely under-inflated. To me this supports my position that tires simply do not "blowout" when properly loaded and inflated. If you have a TPMS you would be warned of punctures or small cuts that allow air to leak out over a period of a couple of minutes. This warning should be enough to allow you to safely pull off the road before there is damage to the RV or there is a loss of vehicle control.

The full episode is available through Netflix or Amazon. The Youtube version I found however does not show the details of their failure to make the tire fail on command.

Defective tire or incorrect diagnosos? (Part 2)

Last time, I discussed how a defective tire could be made. Today I want to show how a failure that is the result of external cause can be easily misdiagnosed. Since there are so many different possible external causes I will only be able to cover a few of the multitude of possible external causes. Please note that these pictures are only a few of those collected during my investigation and many times an on-hand examination is necessary to arrive at the real reason.   Lets start with the example from last post.

Here we see a tire with a sidewall split.

Here is an X-Ray showing the broken bead wire

 

 Here we see the ends of the bead wire showing tensile (pulling) not cut ends.

 Here we see a special tool used to measure wheel diameters. If the wheel were of correct diameter the front piece would line up with the slot in the back piece.

This shows the same tool on a reference rim and you can see an in specification wheel.

While this is an extreme example I think you can agree that the engineers at the car company who are responsible for the wheel being made to specifications didn't want to accept the possibility that their manufacturing plant had made a mistake.  I liken this to RV owners who do not want to accept the possibility that by driving at speeds higher than the tire is rated for or at lower pressure or higher load they might have contributed to the tire failure.

Here are so other examples. 

This tire had physical evidence of puncture and run low but the owner wanted to claim the tire was 100% OK up until the instant the tread came off.

This tire had numerous marks of damage on the inside proving run low.

The tire with this tread throw had an old un-repaired puncture with signs of sidewall contact with part of the vehicles.

 In closing I think a review of an earlier post of a "blowout" will show you that it is a rather common mistake to incorrectly identify the reason for a tire failure.

Defective tire or incorrect diagnosis?

I have been following a thread on a forum for an iconic RV. The company makes trailers that are all silver, but I won't name names. A few of those posts insist the tires are defective because first they failed and second because the owner didn't want to admit the possibility of some external cause as they want to find someone to blame. They will insist that there's "not a scratch on the sidewalls anywhere, and they have never hit a curb or anything else with them."  But somehow two tires failed after 9,000 miles.

The tire pictured here with a very obvious failure was identified as "Defective" by engineers at a large car company. I will cover the real reason in the next post.

I thought this would be a good opportunity to discuss the realities of tire failures and possible defective tires.

While tires are built individually, the various components are made in batches. Depending on the component these batches may be used in 100 to many thousands of tires. So let’s discuss how a "defective" tire might be made.

If it's a design defect then we should see the failure occur in a large percentage of the tires that are manufactured to that specification. Given that in regular production it is not unusual to see 10,000 to 1,000,000 tires made to a given specification it should be easy to see thousands or tens of thousands of identical failures.

A specification identifies which type of rubber is to be used for each of the 15 to 20 different components as well as the type of steel, polyester or nylon to be used. Now it is actually pretty unusual to have a design go into production that results in tires that will fall apart in service. Dozens if not hundreds of tires made to a new specification are tested before a specification is released to production. Additional testing is done by the producing plant to "qualify" the plant to make a specific tire. Even after a spec is released at a plant, modern quality control methods dictate spot checks of production tires. If you research tire recalls over the past few decades you will find that they are not tire design related but either service related or occur in relatively small batches of tires where there was human error in the producing plant on a single batch or two of component rubber not being made to spec.

Another thing that is basically true about tires made with an off-spec material is that they have a very high failure rate, very early in life, sometimes approaching 100 percent. Also the condition of the tires will be essentially identical. You will not see some tires throw a tread off while others have sidewall bulges. Sidewall bulges would all be of approximately the same size and location. If the error was, say, something like the wrong rubber used for the sidewall then I would expect almost all tires made with the wrong compound to suffer the same fate at about the same number of miles and that this failure would be early in life.

Next time I will show some examples of failures that were improperly diagnosed as “defective tires” by tire dealers and engineers working for the auto companies. The tire above is but one example.

Tire Crack or Cut ? CSI - Akron

More than once I was presented with an almost new tire with a claimed "defect crack". I believe that the owner was many times asking for a refund. While the decision to refund the price of the tire or to replace the tire or to deny the claim was not my job. My job was to do a detailed "autopsy" and issue a report. Here is one such case.

A tire was presented with the identified area of concern as seen in this picture. You can see the area of concern does appear to be a jagged crack about 1.2" long.


TIP. To enlarge the pictures to see the "Witness Marks" left by the cutting object right click and select open in new  Tab or New Window. Then you can close the Tab or window and return to this post.


Looking down into the "crack" I noted what appeared to be "witness marks" that would be left by a cutting object. You can think of these much like Ballistic fingerprints left on a bullet by the rifling of the gun. as seen in this picture of a bullet.

For examples and detailed explanation see pg 8 of THIS presentation.

If some object cuts a tire it will leave straight line marks much like those seen on the bullet. If there is simple rubber tear or a molding defect, there will be no such straight lines.



 After deciding where to cut so as to not destroy the evidence, I was able to spread the area open to confirm the presence of the witness marks. There have the appearance of small ridges or lines in the rubber.
Here is the piece I dissected out of the sidewall. You can easily see the lines of the witness marks left by the knife I used to remove this piece.



In this picture you can see the witness marks in the "cut"..







Then I looked at the side of the area and discovered that at its deepest point the body cord was cut.







Cracks in a tire can grow through the rubber but not through body cord.

 The external cut would be in the top of this picture and the "examination" cuts I made are from the bottom.




Closer examination confirm the body cords were cut from some external sharp object and not from any manufacturing defect as seen in these final pictures.

I think you will all agree that there was no defect and that some sharp object cut the tire sidewall.

BOTTOM LINE
Tire inspection is a real science and knowing what to look for and how not to contaminate or destroy the evidence as an inspection is done is what takes years to learn. I think you can also see that having pictures of the whole tire cannot provide sufficient detail to arrive at the "Root Cause" of the tire condition.

How to File a Complaint with NHTSA Part 1

In my last post I asked the question of Why Dont RV Tires Get Recalled? Today I want to outline the process of how to file a proper complaint with NHTSA so there might be an actual investigation started.

 The National Highway Traffic Safety Administration is a part of the US Department Of Transportation. They cover vehicle safety issues. There is an Office of Defect Investigation that looks at vehicle and tire related failures and the ODI has on-line forms you can submit if you think your tire or vehicle has a safety related defect or failure. We will be focusing on tire related issues in this series of posts.

The process:

Data on tire failures is normally submitted by tire manufacturers or importers or vehicle owners. This information is reviewed by ODI and a mandatory recall may be ordered by NHTSA or a voluntary recall may be initiated by the tire manufacturer. Michelin initiated a voluntary recall in the case of the BFG light truck tire recall. If the volume of tires produced or imported in a specific size/type is less than 15,000 there is no requirement for warranty data to be submitted as I understand the rules. If there are a number of valid consumer reports to NHTSA of tire failures, the ODI can decide if a full blown investigation is justified.

If the investigation reveals there was a manufacturing or design defect NHTSA has the legal authority to order the manufacturer or importer to recall and replace the suspect tires. Many times at no cost to the consumer.

Your Responsibility:

Many times the volume of tires used on RVs is well below the reporting threshold so even if there are a number of failures there may no report filed. Also sometimes the importer does not have the organization in place to track tire failures, so if the user doesn’t report the problem there will be no investigation. So the responsibility of reporting suspect tires is yours. Simply spouting off on a RV forum may make you feel better but it will never result in an investigation.

Before you file a complaint:

You need to make an effort to assure the tire failure was not the result of a puncture, impact, leaky valve or due to the failure of some other vehicle part. A review of these posts Blowout, Run-Low Flex, Puncture or Impact will help you confirm the failure was not service related. If a tire dealer says there was nothing wrong with your failed tire ask them to point to the physical evidence they are relying on to make their statement.

Just because you had the tire "adjusted" does not mean you can't file a complaint with NHTSA. I would not be surprised to learn that there have been cases where some tire failures were not reported to NHTSA by the importer.

Information needed to file a complaint

Below is a list of information you will need.  I will use some of the information from the BFG recall as a sample. DO NOT USE THIS SAMPLE INFORMATION. You need to use the correct information or the complaint will be just a waste of your time and will get no results.  

Tire information needed

o    Tire Brand                         (e.g., BF Goodrich)

o    Tire Line                            (e.g., T/A A/S)

o    Tire Size                  (e.g., LT235/85R16 120Q LRE)

o    Component          (I suggest you identify Tread or Sidewall or Bead as appropriate)

o    DOT Number (Tire Identification Number) (Very Important see this example)

·          
















Vehicle information needed         (even if you are reporting a tire, you need the RV info)

o    Model Year

o    Make  This would be the Manufacturer

o    Model

o    Component                       (just select "tire")

o    Vehicle Identification Number (VIN) Found on registration or insurance card and on the placard affixed to the side of your trailer.. 

Now I am sorry to report that NHTSA does not provide the name of every RV or Tire brand in their drop down list. This makes it doubly important for you to provide the correct vehicle VIN and the tire DOT serial in the body of your complaint

It would also be a good idea to get a number of pictures of the tire failure for possible future use. These should be done in full sunlight and you need to be close enough to be just of the tire. If you look at the pictures I have posted in my blog you will see examples. A shot of the failed tire in full shade from 20 feet away will not be of much value. A close-up of the placard will also be of value as it is supposed to have make and manufacturer of the RV as well as the VIN. These pictures will not be submitted to NHTSA unless they contact you but if you end up trashing the tire it will be too late to collect the evidence.

The rest of the process will be covered in the next post. 
 In the time being you could practice and see if you can collect the DOT serial for all your tires and the vehicle VIN. You could even try and take some pictures of your placard and tires to see what it takes so you don't end up with just a black blob.