The "Rule of Thumb" on Tire Life

[RangerJay]

OK folks - need some straight shooting here.

On this and other forums I have read MANY times about the need to change trailer tires after a 5 year life (tops) - regardless of wear.

Went to our service centre today - a large RV dealership that has serviced our trailer(s) for the past 14 years - our PU (1992 - 2003) prior to purchasing our Airstream (2003 to now - from another - very distant - dealer).

Asked about changing tires ..... no question they will change the tires - but the conversation went like this:

Question:
- why do you need to change them ....

Answer:
- you know - the "rule".

Question:
- "huh??? - what rule???

Answer:
- you know - the "rule".

Their follow-up:
- " .... never hear of that .... we'll check them .... but if there is no sign of excessive wear or deterioration then you don't need the change them.

My follow-up:
- "... um .... you know - the rule".

Their closing:
- "we're glad to change them if you want .... but if the aren't showing deterioration or signs of excessive wear .... then you are wasting your money".

My thoughts:
- these folks sell hundreds of units a year .... every year
- we've always been a small customer ....
- but regardless .... we've done well by them - have always felt well served....

Bottom line:
- they stand to make money on new tires but are telling me there may not be a reason to spend it ...

Conclusion:
- I'm inclined to stick with their advice - if the tires pass an inspection then keep'em ...

So .....
- what about this "rule".


Thanks



Jay

[Condoluminum]

All I can offer is dealer either doesn't tow themselves, or hasn't really studied manufacturer info and experience...

Old tubeless tires exposed to sun an ozone will gradually crack and lose integrity, leading to heat or load related failure.. Replacing at 5 or 7 or some number of years appropriate for your conscience and budget and climate and storage arrangements is one way to improve probabilities you won't experience total failure at speed on a freeway... Beyond that, it is a personal judgment call... Know that newer tires fail too, and old ones have been known to NOT fail..

[mistral blue]

For your own personal inspection, take some of the air out and see if you have any cracks developing, check for any unusual wear, tread depth. The "5-year rule" is a rule of thumb. Cliches are cliches for a reason. Good luck.

[Fyrzowt]

I read your post, and just called 2 tire dealers that I deal with. I got the same answer from both:
You should not leave tires on past 6 years from the Manufacture date stamped on the sidewall. There is nothing you can do to prolong this timeframe, but there are things you can do to shorten it.

The code is stamped on the sidewall right after the "DOT" marking. The code is either 3 or 4 numbers long. If 3 numbers long it was built in the 90's and thus too old. The first 2 numbers are the week, the last is the year made.
If you have a 4 place number, the first 2 are the week, the last 2 are the year.

Of course if you have any sign of checking or weathering you should replace them regardless of age.

Good luck,
Dave

On edit: I would also add that if you have a single axle trailer, you may want to be more proactive than with a double axle, however a tire failure on either is no fun.

[dwightdi]

Tire life and potential to fail is greatly effected by the enviroment they have been exposed to. If you are in a high ozone area such as Texas, Florida, California, Arizona, New Mexico, etc and have stored the unit outside, the tires will go bad much sooner. If you have the unit stored inside, that helps alot. If you are in a Northern state such as Wi, SD ND etc, then they will last alot longer. Some tire manufacturers put in more anti ozants than others. Trailer rated tires usually are compounded with better UV and anti ozant packages than car tires. You need to look closely at the sidewalls and treads for cracks. If you find cracks, water can get in and degrade the strength of the cloth and metal belts holding the tire together. If you find ozone cracks, it is time to replace the tire, even if it has good tread. A blown tire can cause thousands of dollars of damage to the wheel well and body of the trailer or may even cause a serious accident. The price of a new tire is cheap insurance.

[flitzwhopper]

so... two levels here: Peace of mind (psychological) and engineering. For the cost of four tires, being much more sure that you will be able to tour the hinterland without event may be worth it. Tires have three levels of deterioration. The first is tread depth which is easily observed. The second is surface deterioration. Even a heavily checked sidewall may only result in leaky tires requiring routine airing up. The final issue is the real deal. The interior - cords, belts and vulcanization are what makes a tire safe or unsafe. Typically, external appearance is a measure of interior health but not always. It is possible to have run a tire under inflated for some of its life and ruin the cords, belts and vulcanization without any observable deterioation on the outside. Hence "the rule". Trailer tires take a lot of load abuse and may be more prone to interior, unobservable, deterioration than passenger car tires. So my advice... for level one, assume level two is true.

[87MH]

Originally Posted by RangerJay

OK folks - need some straight shooting here.....Bottom line:- they stand to make money on new tires but are telling me there may not be a reason to spend it ...Conclusion:- I'm inclined to stick with their advice - if the tires pass an inspection then keep'em ...So .....
- what about this "rule".

Here's another "rule":


"Pay me now, or pay me later"

Do a search on "blew a tire" or "tire blowout".

It's sort of like insurance - pay a bit up front for a new tire or pay a bunch to repair your trailer after you throw a tread or worse.

Having said that, if there are absolutely no signs of cracking or hazing of a 5 year old tire I would probably let it go another year or two....the other side is that there are documented instances of losing tires on maiden voyages.

One of the other overlooked items about tires (besides keeping the proper inflation) is the stem....

My opinion is that anything run over 50 lbs requires a screw type stem and not the rubber insert type....I lost two brand new tires on the E-350 (same side on the dually) and in hindsight I strongly suspect that the problem could be traced back to a rubber set stem.

[mistral blue]

I see you have an '02 Bambi. Two tires. Sorry dude, less margin for error. The fact that you bought it in '03 isn't really significant in my mind either. Even if it had 0 miles on it when you got it in '03. Like Dave suggested earlier, check the code after the "DOT" and let us know what the #s are.

[Beginner]

Cheat
Tires rarely just explode.
Their failure is a progression of events (downward spiral).
With a Tire Pressure Monitering System 99% of the time it will let you know soon enough to pull over without damage to your trailer or rim.
Personal Experience
Beginner

[Excella CM]

I'm all thumbs when it comes to rules, but...

Remember that tires that are run under inflated and therefore overheated have a reduced safety margin and service life. Vigilance is key to tire life. Some tire brands do better than others and have different susceptibility to delamination, etc., but chapter and verse is hard to come by except in an anectodotal fashion. Whatever you buy, whenever you buy, make an effort to monitor tire pressure. Once heat damaged, a tire doesn't "heal" and like a frayed rope should be replaced.

[ArtStream]

Originally Posted by dwightdi

Some tire manufacturers put in more anti ozants than others. Trailer rated tires usually are compounded with better UV and anti ozant packages than car tires. You need to look closely at the sidewalls and treads for cracks. If you find cracks, water can get in and degrade the strength of the cloth and metal belts holding the tire together. If you find ozone cracks, it is time to replace the tire, even if it has good tread.

How can you tell how much anti-ozant you have left, or how much you had originally?

[2airishuman]

hi rangerjay...

the rv dealer stands to make very little on 2 tires mounted and balanced...

considering the time involved, and house labor.

they primarily sell and service rvs not tires...

i consider it a useful convenience & service not a profit center IF the rv dealer will deal with replacement tires...

-check with ANY major tire maker who posts information on rv tire lifespan
-check with any reputable tire shop...

then calculate the cost of fresh tires vs what happens when a tire goes on a bambi, like this one may have...

http://www.airforums.com/forum...rol-17986.html

the person who suggested to keep using old tires is citing another rule of thumb...

but it's the dumb thumb.

Rule of thumb - Wikipedia, the free encyclopedia

cheers
2air'

[markdoane]

Originally Posted by Artstream

How can you tell how much anti-ozant you have left, or how much you had originally?

You can't tell. The rubber is compounded with anti-ozant and UV protectant waxes in the rubber.

After being exposed to air, they vaporize. If you exercize the tires, more of the protectant will be worked to the surface.

Using the tires regularly helps extend the life.

[davidz71]

I checked the date codes on the 4 Goodyear Marathons plus extra spare and found the following:

179 for 17th week of 1999
199 for 19th week of 1999
4301 for 43rd week of 2001
1403 for 14th week of 2003

The 2003 tire is a load range D and the rest are load range C.
The spare is from late 1999 and is load range C but I can't remember the code right now.

All tires look fine and won't be changed until April 2008 when new tires also get new aluminum rims and Centramatic balancers. I realize I am stretching it but right now just don't care. I keep speed to no more than 65 mph and will take the chance.

[RangerJay]

Wow – lots of solidarity here - and fast.

As this thread was running I was searching through the websites of tire manufacturers and large tire dealers to see what they might say on the subject. They pretty much all referenced age as an important factor (from a list of important factors) but were fuzzy on specifics – several provided information on determining the manufacturing date from the tire code that had also been mentioned here in this thread. Michelin was the only one I could find that actually came out and clearly referenced some numbers. Their suggestion was monthly checks after 5 years and replacement after 10 regardless of remaining tire tread. The Michelin guide is located at:

http://www.michelinrvtires.com/michelinrvtires/pdf/RVTireGuide.pdf.

There were a number of other general RV websites that did reference the wisdom of the 5-year “rule”.

The advice here has been good. Clearly there is no question about age being an important factor (out of curiosity I will be check the date code) but the reduced safety margin of the Bambi’s single axle and the challenges of a short wheel-base vehicle win the day for replacing the tires consistent with “the rule”.

I’ll be printing the thread and taking it in to the service centre (Recreation World in Thunder Bay, Ontario). The discussion here doesn’t diminish my faith in them – I’ve never had any reason to complain and they have always gone the extra mile in providing us with good service – and earning our loyalty. I know we will have an entertaining conversation.

On a bit of a side note I read with some interest the recent posts on this forum regarding tire brand – and will be sticking with Goodyear Marathons.

Thanks again to all of you for the advice – this forum has been a significant influence on more than a few of our decisions since buying this Airstream.



Jay

[HiHoAgRV]

Our 8 tired SOB rv had 1/2 dozen blowouts, all on the tag axle except one on the RF. The tag catches almost all of the road debris from the drive axle, gets a hole poked, deflates and explodes. New or old, them's the facts. Ya' never saw it coming (a pressure monitor would have fixed this...). The single other flat was a RF made by BFG (Ben Franklin G?) and popped in a parking lot after a hard turn.

Based on this, the second axle is going to go when ever it catches a nail. An old, cracked, gray sidewalled one is gonna go when IT wants. Use some common sense, keep them inflated, if they look less than new- They Are!

[ROBERTSUNRUS]

Hi, I think five years is plenty of time regardless of miles. Actually the tires will be better off being used than sitting. Unfortuneatly, because I still work for a living, my trailer does more sittting than moveing. It has been rumored that the tire manufacturers want to put an expiration date on tires due to the fact that tires can go bad with time as well with mileage. Think of it as with your car's warranty: Three years or thirty six thousand miles. [WHICH EVER COMES FIRST] Maybe tires will need to be replaced at Five years or 2/32". [WHICH EVER COMES FIRST]
Don't take this wrong, but when a customer asks me about tires, I tell them "At 100 MPH that's the only thing between your vehicle and the street". Most of my customers say they don't drive that fast, but understand my point.

[davidz71]

I don't want anyone to get me wrong concerning my previous post about my Marathons. I would think that 4 year replacement is fine if it makes you feel comfortable but I would feel safe with changing every 5 or so years. I just wanted to state the fact that two of those tires were from 1999. It makes you wonder if the one in 2001 and 2003 replaced an entire set put on sometime in 1999?

I experienced a sidewall/edge of tread blowout with a Carlisle load range D tire on a previously owned '77 Excella 500 31'. All 4 tires were purchased at the same time and were maybe 1 1/2 years old when that occured. No nails or screws were found in the tire to cause a slow leak and eventual failure due to excess heat or flexing of the steel belts. Tire pressures were kept to 62 psi. It just goes to show you that sometimes you experience a tire failure due to unknown reasons even when you have checked tire pressure.

[2airishuman]

hi craig

being aware of tire age is the key issue.

i've never followed an absolute time...

it's progressive, obviously tires age at variable rates...

and past 3 years need more frequent inspections...

travel can be less worrisome and unexpected tire purchases reduced by reqular replacement.

not unlike a lubricant change schedule for the truck...

my concern is that at least one of your times is close to the recall date...

have you checked them for recall?

as bob notes 'time or miles' is already here...

my understanding is the new marathons are in fact warranted for time...

cheers
2air'

[flitzwhopper]

one more thing....

Many of the folks on this thread and forum write about safety inspections. My technicians all carry an infra red temperature sensor both at work and personally. They use it to measure tire temperature, bearing termperature and brake drum termperature among other things. On a recent run to pick up a coach with a friend, we stopped after about 100 miles. One tire was running about 15 degrees hotter than the other three. It was the trailing tire on the street side. Upon checking the tire pressure it was eight pounds lower than the others. Airing it up to the same pressure as the other tires made it run at the same temperature. My techs diagnosed a bad bearing in a trailer they were hauling by "inspecting" them with the termpeature sensor.