Marathon Blowouts and Question

[angerlo]

I suffered four blowouts on our '97 TM 3023 over about 16,000 miles. All occured in 90 plus degree weather on Interstates (three in Florida) traveling at about 62 mph. The first, an original Carlisle could be explained by the age of the tire. Three others were approx 2 year old 14" GoodYear Marathons. Once I was told by the Good Year people that the cause was a defective valve stem made in China. I keep the pressure at 50 psi and check before I travel each day. When not in use the wheels are off the ground and have tire covers. Why the blowouts? The Marathons can't seem to take the weight + the speed + the heat. It's dangerous to change a tire on the side of an interstate. So, I will take state highways as much as possible.

My son, a civil engineer, who works in highway design tells me that Florida interstates have a "coarse coat" for safety. This coarse coat causes more tire friction enhancing safety but leading to more heat. The trailer wheel hubs and tires are slightly less warm on country roads, about the same warmth as my Tundra tires.

To decide what to do, I measured the spaces I have in the wheel wells with a compass and with current tires in place. They are:
4 and 3/4" above 14" Good Year
3" in front of wheel (3 o'clock)
1 and 5/16" behind wheel (9 o'clock)
3/4" from wide part of tire to fender skirt
Weighing TM
Weight on rear axle with weight dist. hitch properly attached 3200 lbs
Weight on rear axle with same unattached 3140 lbs
I was surprised that the difference was not greater.
So, that's 1600 lbs per tire when TM is fully loaded and that includes food, clothing, rear window awning, side awning, AC, hanging cabinet, battery, 3 gal in hot water tank, 1 bike. Spare(s) are in truck. A wheel expert told me that 1600 lbs "is pushing the envelope." The limit for Marathons is 1760 lbs.

I am seriously considering going to Kumho Part #857 Size 205 R14C 8D and using metal valve stems from Napa as shown in previous threads. (Part #90-416 Tubeless Clamp-In Tire Valve TR 416 1 and 1/4" lenght, Fits .453 and .625 rim holes).

An acquaintance recommended 15" 205 75 R15 Trail Master. I cannot find any specs or evaluations about these on the web. Has anyone had experience with these tires? Do they have a greater weight bearing capacity that the 205 Kumhos? I would be happy to know.

My thanks to experts Frenchy, Shrimp Burrito, Wm Tire and others for their helpful discusssions and advice.
97 TM 3023
04 Tundra

[mcgyver210]

There has been lots of talk on tires & reasons for failures If you haven't already I highly recommend searching thru past post.

One thing that seems to always come up though is the need to upgrade to 15" tires which seems to solve most blowout issues. Also the consensus I have gotten is that GT Marathons are fine in a 15".

[Harry Womack]

The 15" also blowout. I lost both of them on my TM and 6 out of 10 of the 15" on our Scout trailers. I switched brands.

[mcgyver210]

The 15" also blowout. I lost both of them on my TM and 6 out of 10 of the 15" on our Scout trailers. I switched brands.

Harry someones just out to get you :D

[ShrimpBurrito]

The more I think about tire blowouts, having both a 5-year-old Marathon and two 3-year-old Kumho blowouts, the more I am convinced there is not a systemic problem with any particular brand. If anything, the problem is across all brands, or ironically, none of them.

As far as I can tell, there are 3 major factors that contribute to trailer tire failure:

- age: the younger the better
- load: the lighter the better
- temperature: the cooler the better

Anytime any of these 3 factors reach high levels, your risk of failure goes up significantly. And if all 3 are high, you are begging for trouble.

I think users of 15" tires have better experience because they increase the margin of error for the load factor. They won't have as many blowouts as early as 14" owners, but they will if they wait too long to replace their tires, especially if they are heavily loaded and town in hot ambient temperatures.

So if you are usually heavily loaded and like to tow in the desert, even occasionally, you need to change our your tires every 3 years like clock work. Not 3.5 years, 3 years.

Perhaps wmtire can chime in as to his opinion.

Dave

[grill-n-go]

For whatever it's worth, my blowout epidemic ended when I got my tires balanced and filled with nitrogen.

[Virginia Deacon]

This bulletin says the speed limit on Marathon ST tires is 65 mph; at speeds from 66 to 75 mph, COLD tire pressure must be increased by 10 psi - not to exceed the psi limit on the side of the tire. The bulletin doesn't differentiate between 14" and 15" tires.

I believe that overloading, excessive speed, and wornout tread on tires all contribute to risk of blowouts. Also, failing to lubricate the axle bearings each season, will add to risk of failure due to overheating.

Last year, I bought a laser thermometer gun to check the axle and tire temperatures at gas/rest stops (Of course, as soon as I stop, the cooling airflow stops and these temperatures start to climb.).

Maybe - as mentioned in the postings - it's not a systemic problem with the tires, but a wake-up call for us to pay closer attention to our responsibilities.

Happy Camping!

[tgpmd1]

For whatever it's worth, my blowout epidemic ended when I got my tires balanced and filled with nitrogen.

Do you have 14" or 15" tires?

Thanks!

Theresa

[mcgyver210]

Ok so if load rating is part of the problem why not use a E Rated tire? Or would the 80 psi pressure cause more issues?

[rumbleweed]

If you dig through the tire posts, it appears that those that tried higher pressure tires found that it reduced shock absorption and caused other structural problems.

[Harry Womack]

I use the load range E tires at 70 PSI. I have not had any problems and the tires do not look low like the load range D tires that blew out.

[[email protected]]

I use the load range E tires at 70 PSI. I have not had any problems and the tires do not look low like the load range D tires that blew out.

What brand/size E -rated tire would replace the 15" Marathons on my 3023? I haven't been able to locate anything but d's.

[Virginia Deacon]

The service bulletin information I cited also says, "Do not exceed the maximum pressure for the wheel." What might that be?

[Harry Womack]

The wheels are stamped 85 PSI max. I am using the Maxxis M8008 ST225/75R15E 10 ply tire. Maxxis # TL15713000. I got them from Discount Tire for around $125.00 ea.

[PopBeavers]

The service bulletin information I cited also says, "Do not exceed the maximum pressure for the wheel." What might that be?
My Goodyear Marathons were stamped either 50 or 55. So adding 10 psi above 65 mph makes no sense at all.

[Harry Womack]

Load Range C tires are 6 ply with a max pressure of 50 PSI
Load range D tires are 8 ply with a max pressure of 65 PSI
Load range E tires are 10 ply with a max pressure of 80 PSI

[mcgyver210]

If you dig through the tire posts, it appears that those that tried higher pressure tires found that it reduced shock absorption and caused other structural problems.

I thought I remembered reading something about that just couldn't be for sure. The Discount Tire guy Recommended I consider E rated tires in the future because he had seen very few issues compared to D rated since trailers are easily overloaded.

I use the load range E tires at 70 PSI. I have not had any problems and the tires do not look low like the load range D tires that blew out.

The wheels are stamped 85 PSI max. I am using the Maxxis M8008 ST225/75R15E 10 ply tire. Maxxis # TL15713000. I got them from Discount Tire for around $125.00 ea.


Hm Interesting no other structural issues?

They also had Carlisle in an E Rated Tire & recommended it over D Rated.

[PopBeavers]

Load Range C tires are 6 ply with a max pressure of 50 PSI
Load range D tires are 8 ply with a max pressure of 65 PSI
Load range E tires are 10 ply with a max pressure of 80 PSI

That being the case, since my tires are stamped 50 psi, then the must be load range C on 14 inch wheels.

I'll check them tonight if I don't forget. But, I no longer have Marathons. I have Tow Master.

[mcgyver210]

That being the case, since my tires are stamped 50 psi, then the must be load range C on 14 inch wheels.

I'll check them tonight if I don't forget. But, I no longer have Marathons. I have Tow Master.

Wayne usually your tires will have the load rating on them also.

Example: 225/75/15-D

[PopBeavers]

Wayne usually your tires will have the load rating on them also.

Example: 225/75/15-D

Good point.

I do know, from the one time I weighed the axle, that when full loaded, more than I ordinarily carry, it weighs 3380 on the axle. I have never weighed each wheel, so it could be unbalanced.

If anyone ever held a rally near home (San Jose) where they weighed each wheel individually I would be interested in attending,.

[Beak12]

Sorry do not know just where this note should be posted. 'So here goes.

Just finished a 3 month 12,524 mile trip with my Elkmont 24----
Marathon Radial ST225/75R15 not one problem.

I checked the tire pressure every other day. Kept 26PSI as posted on the side of the TM. Elkmont loaded for this trip was 4100lbs.

I tried never to go over 57 MPH, except when forced to by traffic conditions. 55 MPH is the legal speed in CA when pulling trailer. I was on the road when the air temp was 45 and as high as 99.

PS: I did have to put new tires on my Outlook. Goodyear at $250 per tire. And I had a flat on my left rear. Nail---:cool:

[PopBeavers]

26 psi sounds rather low to me.

My TM 2720 weighs about 4100 pounds and I inflate o 50 psi.

If I load a little more cargo I will exceed the tire capacity.

[wmtire]

I think it's just a typo. According to the spec sheet, the trailer comes with Load Range D tires (65 psi max), so it was probably 62 psi instead of 26.

P.S. I sure hope the typo is not on the placard from Trailmanor, but I can't imagine the tires holding up under 26 psi if that was the case.

[Beak12]

I think it's just a typo. According to the spec sheet, the trailer comes with Load Range D tires (65 psi max), so it was probably 62 psi instead of 26.

P.S. I sure hope the typo is not on the placard from Trailmanor, but I can't imagine the tires holding up under 26 psi if that was the case.

I stand corrected. And I would like to say it was a typo. But it's just as I typed it.-----So the real information is---the sign on the Elkmont and it reads 65 PSI and that is what I kept it at. And again I hve to say with all those miles I never had a tire problem. :rolleyes:

[brulaz]

John, on another thread in this tire section, I report a difference in tire wear. The passenger side tire wearing more than the other. Especially on the outer edge.

Have you noticed anything similar? We have the same trailer, go about the same speed. And went about the same distance. But I had my tires at 50psi.

Would appreciate your comments.

[clown9644]

One thing I did not see anyone mention is alignment. If the camper and TV are parked so they are in a perfect straight line, the tires on the camper should be in perfect alignment with the tv (you can use a string stretched across the side of the campers tires on the rear of the tv tires) . If they are not they will be running a wee bit sideways increasing wear and a lot of heat! Toe in and out will also, they should be sitting perfectly flat on the surface when on a level surface. An easy check would be a level or carpenters square, level if on very level ground, carpenters square if surface is flat but not level. The more the tire is even and straight, the cooler they run. Nitrogen helps as it is not effected by heat/cold, pressure stays the same. Of course if the tires have been used with proper pressure the wear of the tire will tell the story. If worn inside too much toe in, outside, toe out.

[clown9644]

I just realized I forgot to mention a tires birth date. Yes tires age just like us only much faster. It is suggested that a trailer's tires not be more than 5 or 6 years old, even if it sets in a garage!!!
Here is a short story on the aging process
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=138

This is a 9 minute ABC report on old tires that look new>>> killing people
http://abcnews.go.com/Video/playerIndex?id=4826897

And here is how to check your tires birth date
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

Tires need as much attention, or more than every other component on our TMs!