I dunno what caused this one - I never ran it much over 85, and it's a pretty new tire. It was a DUNLOP AXIOM PLUS P215/70R14 - no speed rating on it anywhere. The spare turned out to be a P215/70R14 96S...

Could heat have been a factor?

I'd like to mention this too: it didn't happen all at once, it gradually did this over a few weeks but going on a 300 mile road trip on I-40 pretty much put the final touch on it. I felt it during the last 200 miles acting like an out of balance wheel (Well no DUH!) but didn't notice it visually until I went out on a short errand and the dang wheel suddenly felt like it was about to come off.

In fact, I found a u-joint problem and was in the middle of replacing them thinking maybe it was a shaft vibration when I noticed something looked odd about the right front tire...

Nothing like riding on the edge, is there?

 

boy thats scary.......are you sure you couldnt get another couple thousand miles outa it???

itsa good thing you found it. seems like it maybe on the back???? giving that you seen it changing the u-joint??

 

Did you mean Dunlop or Maypop?

 

I had two 9.50 x 16.5 General Ameri-Steel's do that but twice as long in the center of the treads, less than 2,000 miles from new failed three weeks apart. Tire pressure, alignment and balance perfect and they failed on a empty driven truck on the fronts at 70mph. Was told later that they had a habit of delaminating. On Dunlop's they seem to have a large slip angle even at 45 psi and require a lower pressure to get a correct foot print.
I did a little electrical at my local tire shop (piped in and installed their new compressor), was given a pair of Uniroyal Laredo 9.50 x 16.5 tires free.
I remember in the 60's / 70's Uniroyal's sucked on passenger cars but I mounted them anyway, boy was I wrong. They air up 48-50 psi vs Dunlop's 24-26 psi for a proper foot print and wear good, going on 50K up front. The Uniroyal's give Michelin's a run far as mileage wear I have found.
Didn't mean to steal thread, sorry.
.....=o&o>.....

 

The way it went down was - I noticed a slight funny vibration from day-1 that I picked up the truck, the last owner said "You might want to check the wheel balance" which I thought was kinda fishy.

It had got a LITTLE worse, around 55 mph, so I was thinking balance problems but no big deal, I'll get to it. Bigger trouble was that it began pulling to the RIGHT.
*TAKE NOTE: It was the LEFT FRONT tire.

So I did a brake inspect on the front and lubed the caliper slides. Still no improvement, so I planned on a brake inspect on the rear as soon as I got back from the ride where (unknown to me) all hell was about to break loose...

On the way home, it was shaking like mad even at 40 mph. I could have sworn a wheel or axle was about to come off! But I was thinking rear of truck, having already gone over the front. I was the most worried though when I got it home, replaced both u-joints, went over both rear brake drums, checked the axles for shaft end-play, and found absolutely nothing that could cause it!

- And then I finally saw the front sidewall.

I figure it must have been gradually swelling out ever since it finally let go in a major way on the last drive. I don't know if putting the truck on jackstands transferred more weight onto them.

Bottom line - I wasn't looking at the front tires because I had already looked them over a few days before.

The thing I get out of all this, is that anymore if I don't see a load and speed rating on a tire - it doesn't belong on my truck. The load (or DUTY) and speed rating are three extra numbers and letters after the tire size, in my case I want to see at least 96S (96=1565 pounds "S"=120MPH) following the tire size. It looks like this:

P215/70R14 96S

On most tires you'll see a load range marked somewhere, but the speed rating is important because a non-rated tire may only be tested to 50 or 60 mph, and many roads are 65 to 75 mph speed limits these days (with a traffic flow of 75 to 85!)

(EDIT) Speed range letters may also follow the second number group in the tire size. An "S" rated tire like the above might also appear like this:

P215/70SR14


PS: She rides smooth as a Continental Mark VII now!!!

 

Only 1565 pounds, that sounds too light for any truck be it a only a 1/2 ton.
On my F250, load range D's (E's will hurt you too damn stiff), 9.50's up front at 2780 pounds, rear 12.50's at 2930 pounds.
I didn't see a speed rating on these LT tires. Have seen the same brand when new go over 140 mph is short speed bursts without problems on a friends blown 460.

.....=o&o>.....

 

"LOAD RANGE" and the number designation in the service description (the "96S" is an example above) are different.

See: http://www.yokohamatire.com/utspeed.asp

I was off a bit on the speed rating too - "S" is only up to 112 mph.

 

I had a tire on a trailer do a similar thing on me a couple of weeks ago on the way to Nashville. The tire looked very similar to yours, except mine actually seperated at the shoulder where the tread transitions to the sidewall so I could see underneath the tread. Looked like the first belt broke along the corner for about 5-6 inches. Didn't lose air, just developed a heck of a bulge. Luckily the exit I pulled off at also had a tire shop that hooked me up with a fresh (used but good tread) tire installed for $21.95.

 

This very well could have been caused by an impact on a pothole or other road hazard. I'd bet on it.

The interior bladder and sidewall belt is compromised, then the air is allowed to get through to the exterior skin.

 

was this tire ever repaired becasue something punctured it?Often times if a tire suffers a puncture, it will eventuall allow water and other element from the road access to the steel belts which results in them rusting and ultimately failing.an un-usually hard hit especially if under inflated will sometimes also allow damage to the internal belts.hope this helps.

 

It looks like the tire was "sidewalled". (ran into a curb) Are there marks on the rim ? Sometimes the radial tire will separate a bit when the sidewall hits a curb, and it takes a while to separate more (blister) as the BuBBle gets bigger. It looks like the tire is about ready to BLOW.

 

I had the inside sidewall let go on a 98 Ranger with factory Firestone Wilderness HT's on it. The OE tires had only 30K on them. I know, I know, the AT's were recalled, but NOT the HT's. I'd NEVER hit anything with the tires, and when I went to get a new set of sneakers for it, the other 3 were about to let go too. Fortunately, I was only going about 40, because when it went down, it went down. Scary part, though, I'd just done a 200 mile trip the previous day pretty much staying in the speed limiter on the Ranger (96 mph). No pop, no hiss, just FLAT. After that, and a previous experience with a pair of Firestone 500's on the front end of a '76 Mercury Monarch (slung tread off both fronts still fully inflated) I wouldn't put a Firestone tire on a wheelbarrow.

You're lucky, so count your blessings that you're still living and lose the other three Dunlops. If one did that, it's a matter of time before one or more of the other three does. Keep the photo, record the air pressure, and get a good lawyer if you wanna take the matter up with Dunlop, but don't hold your breath for anything more than replacement tires. Go get some Michelin XC LT4's to go on the truck if you're staying with OE size. You won't regret it. When I turned in the '98 company truck, it had 70K on the Michelins, and still had that much left I daresay. I'm running the same on my '92 F-150, with about 35K on 'em, never rotated, and still look brand new.

I've done a lotta work in the tire industry, and believe me, it's Goodyears or Michelins for me. I've SEEN how tires are built.

BTW, if those tires were rotated, was it just front to back or have you ever swapped sides with 'em? Some claim swapping sides is OK, but I don't buy that theory, especially after experiencing a similar tread separation like that.

 

Actually - I'm hunting for a set of fifteen inch rims to fit my Rangers lug pattern because a freind of mine outright GAVE me a set of Pirelli's left over from a street rod project when he heard about it. They're designated 97S, which is plenty acceptable.

 

Shouldn't be a big problem, unless they were for a much wider than stock wheel. Otherwise, hit the junkyards, and find some OE 15" wheels. I don't think there's a difference in the lug pattern.

 

Any ford 5x4 1/2 bolt pattern wheel. My dad had a set of crown vic aluminum spokes on his explorer and a guy I worked with had a set of late 70s t-bird spokes on his dads 4x4 ranger.