Tire Guru Help!

[MAMalody]

I need someone to explain to me how to care for tires. I have never had a trouble with tires before.

In '05, I lost a leadng curbside tire in NE, early July around 2:30PM, temperature around 95. Checked tires in the morning, they were the OEM with my 5er, and they were at 78 lbs. Replaced that tire and another with sidewall separation and the stems in the other tires. Lost fender, skirting, gas line and brake line.

I lost a trailing streetside tire in NE a week ago around 12:15PM, temperature around 80. Checked the tires about three hours prior at pullout and they were at 79 lbs. Replaced that tire and the other tire on the axle. These were the tires that I replaced the two in '05. Damaged fender, damaged skiring, and slide seal.

What am I doing wrong?

I routinely check tire pressure and torgue every day that I travel. I also check tire temp at all stops to see if anything is out of line with the other tires.

Seems like all trips of 2000+ miles cost me a couple of tires.

[stiles watson]

Mike,

Have you had the rig weighed? It is possible to overload tires. If possible, weigh each tire separately. There is a maximum loading number on the side of your tire. Weighing each axle won't accurately tell you a single tires loading, but dividing it by 2 will be a start.

How long does you rig set up between trips? As I remember, you are not full time. Tires don't like setting. It has been suggested that tires should not set directly on concrete or asphalt when the rig is in storage. Are they protected from sun light? UV rays seem to shorten tire life.

I now pay close attention to when the "new" tire was manufactured. the date is embossed on the side of the tire. It is found in the string of numbers after "DOT". The last four numbers indicate the week of the year and the year of manufacture, i.e., 2106 means the 21st week of 2006. I would not mount a tire more than a year past the manufacture date. Rubber has a live time.

There is a direct relationship between loading and tire pressure. Online, you can find a chart showing maximum loading at different tire pressures. E-rated tires inflated to 75 psi rather than 80 psi lose load capacity. Under inflation by even a few pounds can cause problems.

In the hot weather, speed also seems to affect tires. I try to keep it at 58 to 62 mph. And of course, the quality of the tire is important. It sounds as if the tire you are now using may be suspect. Others will share their preference as to brand.

• Loading
• Pressure measured at cold (less than a mile)
• Age
• Protection in storage
• Quality
• Speed

Are all factors to be considered. There may be others. I have learned that for proper inflation, I need to know the loading. This can only be obtained by weighing the rigs individual tires.

Having had to blowouts that caused damage like you describe, gives me empathy for your plight.

[Glenn and Lorraine]

I spent many many years selling and servicing everything from small trailer tires to large truck tires and most every kind of tire in between.
Some of what Stiles posted above I do agree with but...

quote:I would not mount a tire more than a year past the manufacture date.

Most all tires begin showing their age at about 5 to 7 years. A tire that is just a year old is not going to be an age problem.

quote:It has been suggested that tires should not set directly on concrete or asphalt when the rig is in storage.

I know of no reasonable reason that a tire cannot sit on concrete or asphalt. I have sen tires that sat for a couple years on either of the above with no noticeable negative effects.

quote:Are they protected from sun light? UV rays seem to shorten tire life.

This is true but not enough to bother to cover tires to protect them. As I had said "Most all tires begin showing their age at about 5 to 7 years." A tire exposed to the sun may have it's life shortened by maybe 6 months. Surely not a problem in the above situation.

quote:I have learned that for proper inflation, I need to know the loading. This can only be obtained by weighing the rigs individual tires.

As far as load and air pressure. I totally agree. Mike, your Monty came from the factory with tire size LT235/85R16 load range E. At a max inflation of 80 PSI the load range per tire is 3042# per tire. The same tire at 75 PSI drops the load capacity to 2905#. While the difference is only 137# that is a significant difference if your trailer is loaded to the max. An under inflated tire does a lot more flexing which is friction. Friction creates heat in a hurry. Heat builds pressure and that kind of pressure will blow out even a brand new tire.
Knowing the weight carried on each tire is important but getting that precise is tough at best and than every time you move something around or remove something from the rig or fill/dump a tank these numbers become meaningless. Starting your venture with empty tanks is one weight but the minute you stay in a CG with water but no dump site changes everything. I would suggest you try to keep a balanced load in the trailer and than knowing the total weight being carried by all 4 tires is about the simplest way to go. Divide that number by 4 and adjust the pressure accordingly. No it's not the best solution but it is the easiest solution.
Speed absolutely has an effect of tires especially so on a hot day. Keeping your speed at 55 to 65 can make a world of difference. Tires rolling down a hot hiway at 70 to 75 MPH can cause problems. During those hot hot summer days make more frequent stops to cool things down such as the tires, engine, transmission, rear end, the driver and the spouse. But never ever check your air pressure in a hot tire. The absolutely best time to check air pressure during the hot summer months is first thing in the morning before the sun is out.

[TLightning]

I'm not a full timer, but here's what I do:

-Run max pressure, even if not at max weight.
-I store my trailer in the shade and run the tires up on plywood off the concrete.
-They will dry rot and crack long before the tread wears out.
-Most ST tires are speed rated to 65...I cruise at 62.
-When camping, I cover them to keep the sun off them.

I realize some of what I do may not be necessary and may not even help, but I've done it for years, and it works for me...so I'm sticking with it.

[LonnieB]

Mike,

In three hours of travelling, you could have very easily picked up some sort of debris from the road that caused your tire to loose pressure, overheat, and blow out. The rear tires are especially vulnerable, as the lead tire can cause a nail, or other object to pop up and stick in the rear tire as it rolls across the object. I'm not saying I believe this is what happened, but if your tires are in good condition, not overloaded, within rated speed, and properly inflated, it's a strong probability.

I seem to remember a post you made a year or so ago, about replacing tires 2 at a time on your TV, and rotating the old tires down the line from TV to RV, front to rear. If this is the case, are the tires being put on the RV within their "age limits"? You also posted more recently of cracks in your tires. Did you have them checked by a professional?

Being in the tire business, and selling everything from 15 dollar apiece wheel barrow tires to 7 thousand dollar apiece tractor tires, I have seen every type of tire failure you can imagine. Improper inflation, overloading, road hazards, and exceeding the rated speed, are the four most common problems I encounter.

All that being said, I would add that I agree with Glenn 100% on his post above.

[billhoover]

An old guy that ran a tire shop for years told me the three things that cause tire problems are low tire pressure, low tire pressure and low tire pressure.

[MAMalody]

Thanks for the input. It turns out that the tire rotation with my TV turned out not to be the thing to do. It seems that I read the tire sizes wrong and my TV tires were too tall for my 5er. The two tires I replaced were three years old by the date stamped on them. A month earlier this year I replaced two tires (they are the 5er leading tires) and the trailing tires were judged to be okay. My 5er is stored in my back yard on a gravel bed. I take it out about once a month. My trips are from three days to ten days at at time. My trips are only about 300 miles round trip unless the trip is over three days. Those trips are up to about 1500 miles round trip. I cover the tires if my down time will exceed one week. I don't run from Nov 15 through 28 Feb. When that time comes I back the trailer up on plastic blocks. I run about 60-62 mph. I seem to stop every two hours or so for about 15-30 minutes. I must admit that I run pretty close to maximum load. When I check tire pressure before leaving it is usually around noon and I put the psi at 80. When on a run, I check around 8AM. As long as the pressure is over 78 psi, I don't usually mess with it. My thinking has been that that is a colder part of the day and the pressure will read a little lower that it would be for the greater part of the day.

[Glenn and Lorraine]

I feel you had some sort of a road hazard failure. Either a nail puncture or a small piece of metal causing a slow leak. As you were unaware of this leak you continued on your merry way. The pressure continued to lessen and the tire failed from the low pressure. Having this happen a second time is nothing more than coincidence. I cannot see where you are doing anything wrong.
As far as "When I check tire pressure before leaving it is usually around noon and I put the psi at 80. When on a run, I check around 8AM. As long as the pressure is over 78 psi, I don't usually mess with it. My thinking has been that that is a colder part of the day and the pressure will read a little lower that it would be for the greater part of the day." Unless you are referring to freezing temps, your temp during the cooler hours should be set at 80PSI. Do not try to compensate by leaving them set at 78 because they will increase as the day warms up. Even after warming up your tires will still be 2#s under inflated.
ALSO, when checking air pressure ALWAYS use the same tire gauge. Never ever trust the tire gauges on the self serve air pumps. As far as a neighbors tire gauge, many gauges can be off as much as 5 pounds.
ALSO, many of the more reputable tire shops use the more expensive gauges, we had a master gauge that was exact to within a half pound, and these gauges are much more accurate than the ones most of us carry. Take your tire gauge to one of these tire shops and ask them to compare their gauge to your's you may find your's is way off and needs to be replaced.

[MAMalody]

Thanks for the inflation info. As you can tell I don't know a whole lot about tires. I will keep that in mind.

[DONnANNIE]

Mike, just one suggestion as no one mentioned it. You might consider a tire pressure monitor system. At least it could give you early warning of a low tire and you could stop before any other damage occurs.

[MAMalody]

That's an idea. Do you have a system? What kind is it? Approximate cost? Did you also set up your TV?

[DONnANNIE]

quote:MAMalody Posted - Jul 10 2008 : 01:23:43 AM
That's an idea. Do you have a system? What kind is it? Approximate cost? Did you also set up your TV?

I have the original Doran Pressure Pro system. It cost $591 for the receiver/monitor and 8 sensor/transmitters for the TV & 5er. Doran has dropped Pressure Pro for their own new system called Doran 360RV Tire Pressure Monitoring System.(I don't know anything about the 360RV)

Pressure Pro System
http://www.pressureprosouth.com/file...reprohome.html

Doran 360RV System
http://www.doranmfg.com/PDF/Doran360RVbrochure.pdf

On a recent trip to Lincoln Rock St Pk East Wenatchee I lost the signal from the right rear trailer wheel after about one hour of travel. I didn't know what happened. The only indication I had was a flashing red light on the monitor - no alarm. I stopped and checked the tire and the pressure was 90 psi. I think all I needed was a better location for the monitor to pickup the signal. It is well worth it for the peace of mind.

[simonsrf]

Mike,

You might also check the DOT date code on the new tires. I just recently bought 4 new tires and specified that they had to be '08 date code. They tried to sneak a late '07 in there...Beware!...and good luck.

[PowellsMonty]

We have an Expedition that has 70000 miles on 9 yr old Michelins that still have over half of the tread on them. Sidewalls not cracked, look new. Should I replace them because of age?

[Glenn and Lorraine]

Inspect them really close or take the rig to a reputable tire dealer. The key word there is "reputable". Not the local corner tire shop/convience store, not the Wal*Mart or Sam's Club. Find a dealer that sells tires full time and not someone who just happens to also sell tires along with numerous other services. Typically these reputable dealers are in the business to take care of a customers problems without trying to sell you new rubber. Granted there are some out there that are in it for the money but if you pay attention to them the sales pitch will enter into the conversation at a very early stage. If they are too quick to try to sell you new tires leave and get a second opinion.

BUT, with 9 year old tires and 70,000 miles I would seriously be considering new rubber. 5 to 7 years is a good rule of thumb but 9+ years is not out of the question After 9 years you could get another year or more but there is no telling when they may fail. You could be pushing your luck.

ON EDIT
While the above has been my belief I now strongly recommend viewing the following 20/20 video on Aging Tires.
http://abcnews.go.com/Video/playerIndex?id=4826897