Thoughts on tire blowout

[EK]

I had a tire blowout on my 1997 F-250. The sidewall had a blowout on a straight level road about 55 mph. No obvious external damage to the tire. The tire was a Nokian Haka 10LT with about 19k miles on it. Image 1 shows the sidewall blowout. Another point of interest these tires have irregularities in the sidewall, as shown in second image. Here are the images… [IMG]http://ekangas.myphotoalbum.com/view_album.php?set_albumName=Nokian_tire [/IMG] Anyone else experience anything like this? The tire dealer said this failure had nothing to do with the sidewall irregularities. He indicated that it was due to a weakened tire. Thoughts?

 

[Matt_S]

I've seen those "irregularities" myself. I was told it's where the belts in the sidewall are joined together and it's fairly normal. IMO, it shouldn't be that way. If you're confident that the tire was at the correct pressure and wasn't overloaded, I'd say it must be a defect.

 

[CapriRacer]

I'd really like to get a photo of the inside. But doing this without: 1) The second photo shows what is known as sidewall indentations. It's where the ply fabric overlaps and rather than bulge out, it is indented because it has more fabric there. 2) Notice that the split in the first photo is ragged and not smooth. If this were the result of too few cords (the oppositie of the indentation), then the split would have bulged out and the failure to be extremely smooth on the edges. This leads me to believe that this is the result of an impact. You could confirm this by looking on the inside of the tire and if there are a pair of marks that are circumferential (90 degree to the split) - one about 25% of the way up the sidewall and one about 75% up the sidewall - then that's where the tire bottomed out against itself. BTW - the absence of these marks just means the impact theory is uncomfirmed, not excluded. Hope this helps.

 

[1sttruck]

What load range are the tires, and what pressures did you usually run ? Did you run them all year ? One problem that turned up with a quick web search were some thin sidewalls on some Nokians in 1999.

 

[k1xv]

I have the same brand/model tires in 245/75-16 load range E purchased in late 2003 and the sidewalls do not have the irregularities shown in the picture. My Nokians are marked made in USA and I know that they are made for Nokian by Cooper in Ohio. Where are yours made?

 

[Fuelrod]

The indentations are caused by tight cord wraps (remember these are radials and the cords all run in the same direction) and are quite common in radial tires. A minor manufacturing imperfection prevelent in some brands and absent in others.. The sidewall rupture (all radials have tender sidewalls, their greatest weakness) usually starts by rubbing up against a curb. This tends to pull those radial cords apart creating a weak spot in the sidewall....

 

[EK]

Thanks for the responses. The tires were purchased winter 2002. I run them in the winter with some overlap in the spring. They are taken off for summer. The truck is loaded with less than 1000 lb in the winter. The tires are LT235/85R16 load range E. I inflate the front to 48 psi and the rear to 38 psi. The tire that failed was on the right front. The tire is made in the USA. I do not know how to decipher the codes to know the specific mfg location or date. Any thoughts on tires that are more durable and less likely to suffer such a failure?

 

[1sttruck]

Tough tires ? After reading reviews while looking for some winter tires (17in load range E winter tires are hard to find) some that come to mind are the Michelin 'Traction' tires, BFG M/Ts, Goodyear MT/Rs (? mud/rock tire), and the Toyo M55s. The BFG AT/KOs are very popular, they're severe snow rated, but if you look they have reports of blown sidewalls too. My stock tires on a Dodge 2500 are Michelin A/S 245/70-17s, load range E, and they're spec'd for something like 50 to 80 psi front, 40 to 80 psi rear, from light to full load, and an extra 10 psi for driving over 65mph. Since I have a canopy, some seats in the bed, bunch of tools and stuff, often have 6 people and stuff, I assume that I am less than half loaded (the truck :^) and drive over 65mph often, so I run something 65 psi front and 60 rear in town and add 5 psi to both on more extended trips. I prefer to minimize tire stress and to suffer comfort and a bit of traction. The tires are ok on snow and useless on ice so airing down doesn't seem to help much. On my 265/70-17 winter tires (Cooper M+S) I'm running about 60 psi front and 55 psi rear, I'll add 5 psi for road trips, as the larger tires need less air.

 

[k1xv]

I tend to run a little more pressure in mine, more like 55-60 all the way around in a Crew Cab GMC 2500HD 2003 Duramax. They are made by Cooper for Nokian in their Findlay Ohio plant. Quite frankly, yours is the first case I have heard of regarding a Nokian tire failure. I would avoid Firestone, though the Bridgestone REVO is considered a top rated light truck tire. Its a shame you have lost confidence in Nokian, as they are widely recognized as the best winter tire.

 

[EK]

I took a look at the tire with the tire shop. The man at the tire shop who I have known for 30+ years could not show me any specific cause for the failure. He looked closely at the inside of the tire but could not find any evidence of damage or marks of any kind anywhere inside the tire. I added an image of the inside of the tire... [IMG]http://ekangas.myphotoalbum.com/view_album.php?set_albumName=Nokian_tire [/IMG] I am taking the tire to another dealer for a second opinion. An unexplained blowout does not give me confidence in these tires.

 

[k1xv]

Whatever you do, do not give up custody of the tire. Even though you (thankfully) did not suffer any personal injuries, I am sure that the tire manufacturer would prefer that you not have it. Have you contacted anyone at National Highway Traffic Safety Administration, or do you intend to let it drop?

 

[Ray Garlington]

There is a good chance you ran over something that puntured the side wall (looks like a clean cut toward the tread). Once the sidewall starts to split, you lose air and rapidly beat the tire to pieces as you slow down. I had a similar 'failure' where something came up through the tread near the edge and cut small hole in the sidewall (speed: 60mph). By the time I stopped, the tire was split similar to yours at the puncture site. I did not discover the cause until I dismounted the tire, and found remnant of the thing that caused the tear.