Kumho blowout!

[ShrimpBurrito]

I had a blowout on a Kumho Radial 857 trailer tire today. I believe I have the honor of being the first on this forum to do so, so I sort of feel honored. The details:

1. blowout occurred 80 miles into the trip today
2. I had checked tire pressure before leaving, and confirmed it to be around 63 psi. According to Kumho, that should have given me a load rating of 2146 lbs per tire, or ~4,300 lbs total. I haven't weighed my TM yet, but given a generous gross weight of 4,000 lbs and a conservative tongue weight of 600 lbs, that would mean only ~1,700 lbs on each tire, well within the rated range.
3. We were loaded as we always do for thousands of miles and probably 30-40 trips -- toilet charged, fresh water tank and hot water heater full, and a 3 drawers of clothes. Fridge was stocked, but that's about it. The cabinet under the rear bed is mostly empty, I have 2 T-105 batteries, pots and pans, and 3 camp chairs.
4. the tires were 3.5 years old based on date of manufacture. They had been in service for 3 years, and had been used regularly, on average once a month, but a few times (maybe 3) they had gone without being moved for 3 months.
5. I was going 60 MPH
6. It was about 65 degrees at our house when I left; within 1 hour into the trip, it was 98 degrees outside, so we had been running in that temp for around 1.5 hrs
7. It happened on the passenger side, so my new shield around the plumbing that I installed THE DAY BEFORE YESTERDAY wasn't tested.
8. This blowout happened on the same side as our first blowout with a Marathon, which presumably has a lighter load than the driver side due to no water.
9. I had just repacked the bearings about 6 weeks ago. We did a 15-hour roundtrip drive immediately thereafter in 70 degree temps, and the hubs were lukewarm at best; definitely no where near hot.
10. Both tires, wheels, and hubs were very warm. I could grab hold of the hub for a good 30 seconds before it starting getting uncomfortable.
11. It appears the tread separated, but there is what appears to be a transverse tear across the tread. I'm not sure if that is a cause or effect.
12. my custom made replacement wheel well (with no wheel well modification done) worked like a champ. 14 or 16 gauge (I can't remember) galvanized steel, welded at all seams. Zero damage, and barely even a scratch to the well.
13. I looked for any physical signs of foreign objects that would have contributed to failure, but didn't see anything.

Amazingly, between changing the tire myself and getting the spare replaced 5 minutes down the road, we were only delayed 90 minutes. But unfortunately, I think, they did not have any Kumhos. So I ended up getting a Maxxis 205 75/R14, but it's max load capacity is only ~1750-1800 lbs at max psi. Plus, it's a slightly smaller tire than the Kumho -- probably an inch smaller in diameter -- so if I ever have to mount it, I'll be towing with 2 slightly different sized tires. Probably not a huge deal, as the doughnut spare tires are way smaller than regular car tires, and you can get around just fine.

I'm not sure what to do at this point. I concede that the tires are getting up there in age, but I didn't think I was at the point of risking failure. So what was the problem? And what should I do? My options as I see:

keep going with existing setup, with two 3.5 year old Kumhos and one lesser load rated Maxxis -- we have 7,500 miles left on this trip.
dump the Kumhos and get 2 new Maxxis tires to match the spare, although this puts the load rating back down to what the Marathons were.
chalk it up to age, and buy 3 new Kumhos, and try to sell the spare back to whatever deal I buy them from.

I should note that I will be at the TM factory next week, but that's a few thousand more miles down the road. I'm not sure what my options are in upgrading to 15" wheels. I have the older style wheel wells, and I am very close (maybe 1" IIRC) from the frame cross member in back of the wheel. My TM tracks very slightly to the right due to the factory welding the axle about an inch or so (IIRC) further back on one side vs. the other. Could that contribute to failure, or would that just result in uneven wear, similar to a car out of alignment?

What would you all do? We continued on for another few hundred miles, where the temp ranged from the mid 90's to the low 100's. We're just outside of Vegas tonight, and we're headed to Utah tomorrow, where it is supposed to be just as hot.

This is very, very frustrating.

Dave

[B_and_D]

I'm not sure about going to the 15" wheels at this point in your trip, but I would definitely get a matched new set of tires. You could always keep the Maxxis as a "spare" spare, in case you have another blowout, and can't find a tire to match the others. You could order one to match at that point and pick it up along your way.

Sorry to hear this, I hope the rest of your trip goes blowout free!

First thank you for all the information and the pictures!

Boy does that look familiar...

FYIW there are some nuances with the trailer that may have contributed along with temperature and weight and tire age but I am not saying any of those single factors caused the blowout. Even combined it does not seem like enough. If that were so I would be expecting the other tire to pop as well. Like on the same trip, same day, as has been stated in other posts. From reading your many past posts I can tell you take good care of your TM. I do not think it is anything you could have avoided. From looking at the pictures, and this is a guess, looks like the tires working environment that day and age may have been getting close to the limit and that particular tire hit something to weaken it where the transverse tear is. A deep, wide crack in the road maybe? Maybe not even hit on that day? I have heard that sometimes a tire can take a hit and keep going for a while before the damage shows.

As for what to do... If it were me. . . get another class D tire on that spare asap to get you through the trip. (I carry two spares just in case - crazy I know but... )

For the future . . . If you could go to 15 inch tires??? I have told myself that if my own personal 14 inch class D tire experiment blows up in my face or under my TM I would go to 15's next.

Very sorry to hear about the blowout. Very frustrating I am sure. Get on that computer and search around your next stop for a class D 14 and best of luck to you on the rest of your journey!

Thanks again for the post!

"My TM tracks very slightly to the right due to the factory welding the axle about an inch or so (IIRC) further back on one side vs. the other. Could that contribute to failure, or would that just result in uneven wear, similar to a car out of alignment?"

??? An inch ??? Good grief, is this common? Our Elkmont tracks pretty well so hopefully they are a bit more precise these days.

I would think that any uneven wear indicates some stress on the tire.

[Wavery]

If it were me......I would install the lift kit and 15" wheels today......I would not risk ruining a nice trip like that over $500 or so. I'd just do it and be done with it........in fact, after reading this story, I will NOT make a long trip on my (now 1 year-old) 14" tires.

For our next long trip, I will do the upgrade ....100% guaranteed. I think that if you don't do it now, you will always be concerned about it. Not worth it, in my mind......

I'm really sorry this happened to you but it is a big help to me........ I have been kicking myself ever since I purchased my new 14" tires......

EDIT.....Is that a rubber valve stem on the tire that blew???

I am also suspicious of the fact that you are running a WDH. I hold to the theory that the shock-loading, on tires that are close to their maximum rating, may just be too much and lead to premature tread separation (which is what we are seeing in most of these incidents).

Looks like a rubber valve stem, bend to each side & check for cracks, if any, replace with metal valves & run with the same setup. Most problems have happened thanks to our asian junk valve stems! Replaced all 3 of mine before last summer & 2 were very badly cracked in both directions when bent to both sides.

Dave, Just curious, do you store your trailer outside or inside? If outside does the tire get a lot of sun? The roads can be poor, I wonder if they got pot holed. Robert

[Wavery]

Originally Posted by robertkennel

Dave, Just curious, do you store your trailer outside or inside? If outside does the tire get a lot of sun? The roads can be poor, I wonder if they got pot holed. Robert

The Sun won't cause tread separation on a 3-year-old tire. Pot-holed....used a WDH....possibility.....

[ShrimpBurrito]

Thanks for all the responses. Just got back into an area where I can get internet with my computer so I could respond, however, I did read your responses right after they were posted. And for about a day and a half after reading those responses, my thought process was that the blowout was a fluke -- as Joseph eluded to, simply a combination of unfortunate series of events. The tire age, although not real old, not real young either, the fact that ambient air temp increased about 35 degrees in 2.5 hours, and the fact we went from sea level to ~1,500 feet in the same time period. Again, none of these factors should be an issue by themselves, but combined, perhaps they could cause a blowout. After all, the Kumhos had given me 3 solid years of infallable service.

But on the 3rd day, I got some good news and some bad news.

The good news: the plumbing shield I installed just a few days ago works.
The bad news: I had a second Kumho blowout about 48 hours and a few hundred miles after the first, this time on the opposite side, with the plumbing. The only remaining "unblown" Kumho was the spare, which by this time only had a few hundred miles.

This time, there are more tears in the sidewall, so I don't know if that helps isolate the reason for failure. I've attached pics of the second blowout. I'm hoping Bobby/wmtire will chime in here with his expert opinion. But being the second blowout in 48 hours, I quickly concluded that my "series of unfortunate circumstances" theory was wrong, and that clearly there was some other issue with the tires. Our elevation hadn't changed significantly, and the ambient air temperature had increased only 5 degrees since I last checked the cold tire pressure. Since all aspects of our towing configuration were no different that day than any other day in the past 3 years of trouble-free service, I concluded the failure was at least not related to elevation, ambient air temperature, or load.

Of course, it happened late Saturday afternoon, so many retail tire stores are already closed in Grand Junction, CO, and ALL tire distributors are closed. That means I am limited in what I buy to what whoever is still open happens to have in stock. It would have happened on a Sunday night on the 150-mile stretch of road in eastern Utah where there is ZERO civilization of any kind, so in that sense, I was lucky.

After some careful measuring and a test mount, I heeded the advice of many here on the forum (including Wayne in this thread) and upgraded to 15" wheels. Fortunately, I already had the lift kit, so that was not an issue. Not only did I not know of any other option, but given my choices on that day, it was my ONLY option. Since the only 14" tires I could find only had a load rating of ~1,800 lbs (which was the exact reason for going to the Kumhos to begin with), it was either get 3 of those, or go 15".

Unfortunately, the only 225 75/R15 they had in a trailer tire was a Carlise. I know, not ideal, although I seem to recall reading rumors that they are much improved over their previous disasterous reputation. But with a load rating of ~2,850 lbs (load range E), I am thinking I have a very large margin for error, and hope that will keep me out of trouble. And it wasn't really a choice....it was either the Carlise, or spend a few nights in Grand Junction till the distributors reopened on Monday, which was not an option.

The closest clearance on the 225's is at the wheel well covers -- it's only maybe 1/2", MAYBE 3/4". I put a half dozen flat washers between the TM and the cover on the bottom 2 screws to push the cover out a bit to give more clearance. I then chalked the sidewalls so I could easily tell if they were rubbing, and so far, so good. I wouldn't really expect the sidewall to flex very much on the top half of the tire, so I think it will be fine. And the tires run fairly cool. No more than luke warm on a 85-degree day.

The dealer only had black rims, and he added chrome lug nuts. I'm not a vehicle stylist by any means, but it looks snazzy. I can take pics if anyone is interested.

Dave

[B_and_D]

Hopefully these will get you through the rest of your trip and your trip "bad luck" will be over with and you can thoroughly enjoy the rest of it without further incident!

I am glad to hear that your plumbing cage worked, but on the other hand it doesn't look like too much came off of that tire before you pulled over & stopped? When we had our blowouts the whole tread section came off right away (in one big piece) and that's what caused the damage.

Good luck to you, and keep us posted on your adventures!

Dee