Community Forums

RJEV · 10-12-2010, 05:59 PM

We had a flat tire while at our site at an RV park. While trying to air the tire blew. We have a 2008 Allegro 32/Ford with 19.5 Goodyear tires with 12000 miles. It is not overloaded, weighed twice, and tire pressure kept at 88 psi. As far as I know I haven't hit anything. The tire had a small nail in it but not at the point where it blew out, which was on the tread and not the sidewall.

Two questions: Should we be concerned about the integrity of the other tires? I've checked and see no damage or unusual wear. However, I don't have any faith in the other tires since after only 12000 miles and always proper inflation we apparently had a failure.

The replacement tire is a G rated tire which seems to set a little higher than the F rated tire although it may appear that way since it is new and has more tread. The tire replaced is on the inside rear. Should running a G rated tire beside an F rated tire pose a problem?

Should we bite the bullet and replace the remaining 5 tires with G rated tires?

Suggestions and thoughts appreciated.

Thanks,
RJ

GaryKD · 10-12-2010, 06:13 PM

Hi RJEV,

You do not say the environment the tires spend their life in. My assumption is you purchased the 08 coach new, in 08 and know the history of the tires. The coach is 2 or 3 years old. With 12K miles the coach sits a lot of the time. Do you:
1. cover the tires when not in use
2. use a tire coating to protect against sun damage

The bottom line is if you have taken care of the tires the blowout is, most likely, an isolated incident. I would not purchase additional tires. If the tires have been exposed to the sun all the time, without any additional protection, consider having them inspected and possibly replaced.

RickO · 10-12-2010, 06:29 PM

I would share your concern about the integrity of the remaining tires. I would do as Gary suggests and have them inspected but I might call Goodyear first and see what they say.

Rick

Wanabee FTer · 10-12-2010, 08:42 PM

In my previous life, I was an automotive service manager. What I saw that caused most tire blow outs was usually caused by a nail or slow leak that went undetected during normal driving conditions. Driving a vehicle with low tire pressure causes the sidewalls to overheat and damages the tire construction. After the vehicle sits a while the tire may go all the way flat. Then when the tire is aired up it could soon blow out.

leadman · 10-12-2010, 09:23 PM

wannabeFter is correct. The sidewalls overheat and also the air will seperate the plies of the tire from the site of the puncture. This is why the old plugs are no longer used. Either a patch or a patch/plug combination is installed from the inside of the tire.
The new tire should not be left on the same position as the old tire. The load ratings should be the same and diameter of the tire has to be closely matched to the other tire when used as duals. The new tire is going to be carrying most of the load as it is taller.

Wanabee FTer · 10-12-2010, 09:31 PM

Actually the site of the puncture is the cause, the sidewall damage is the effect. The sidewall can be damaged even if there is no puncture or nail. It's extremely low tire pressure that causes the damage.

Hikerdogs · 10-13-2010, 07:19 AM

First of all if the tires are the same neumerical size they will be the same physical dimensions. The only difference between F and G rated tires is the maximum amount of weight they can carry. We had 245/70R19.5 load range F Goodyear G670s on our motorhome when we bought it new. When the fronts had to be replaced we used the same size and weight rating tires. When the rears were replaced we couldn't find any F rated tires so we went went with the same size G rated tires. This combination worked well for over 42,000 miles. An alignment problem later dictated a front tire be replaced so we replaced both with load range G tires.

I would move the new tire to a steering position and put the "worn" steering tire on the rear axle with the other "worn" dual. Most manufacturers warn against pairing a new and used tire on the same axle position. The new tire will be slightly taller since there is more tread and as such will carry more than half of the weight in that position. By carrying more weight it will heat and wear faster, and may also flex enough to rub on the other tire.

Gary RVRoamer · 10-13-2010, 08:06 AM

I agree with Wannabee - the tire sidewall was no doubt damaged by driving with low pressure, which was caused by the nail leak. I would not be concerned about the other tires.

powderman · 10-13-2010, 08:31 AM

If not changing the tires out, a TPMS might be in order. Now that I think about it a TPMS might be a good idea even if new tires. I know I will soon be getting them on my 5er.

leadman · 10-13-2010, 09:20 AM

Yes, the puncture is what caused the problem creating low air pressure, which causes the tire to overheat due to extreme flexing. The duals can then also rub together causing additional problems and the other tire can be affected by the friction caused by rubbing that creats heat. Not uncommon to have one dual fail then have the other dual fail also from the original failure rubbing. This type of failure is called a "zipper" failure as this is what it resembles.
There have been tire failures caused by the original tire size being replaced by a larger tire but the spacing between the tires was too close and even though both tires were good and properly inflated they rubbed and failed. On semi trucks and trailers there are spacers available to correct this problem without changing the wheels, might also be available in sizes for motorhomes.