By Mark Polk
RV Education 101
When a tire on a motorhome fails, it can be extremely dangerous and can cause extensive damage to your RV. Reasons for tire failure include under inflation, over inflation, overloading, and the age of the tires.
In this Top 7, I’ll discuss how the age of your tires -- and their exposure to the elements -- can lead to tire failure. And I'll explain what can be done to prevent aging tire failure.
Idle tires age faster
Tires are designed and built to be used. The rubber used in tires ages faster when the tires are not used, so more use results in longer tire life. The problem is, many motorhomes don’t get used that much.
Tire manufacturers add compounds to help protect the rubber from weather cracking and ozone damage. But for these compounds to work their way to the surface of the tire and help protect the rubber from damage, the tire needs to be rolling down the road, heating up and flexing.
When tires sit still, as when a motorhome is in storage, they start to dry out and age faster.
Weather cracking or checking occurs on all tires when they are exposed to heat and sunlight. This is especially true of a tire’s sidewall.
Ozone in the air and UV rays from the sun shorten the life of your tires. It’s not uncommon to see motorhome tires with low mileage and plenty of tread that are ruined by the effects of ozone and UV rays. Ozone and UV rays cause tires to weather crack and dry rot. This damage occurs faster in tires that are not used much.
Inspecting your tires: what to look for
Before each trip, inspect your motorhome’s tires for weather checking or cracks in the sidewalls. Cracks less than 1/32-inch deep are okay, but if the cracks are more than 2/32-inch deep the tire should be replaced immediately. If you notice damage to the tires and you’re not sure what the extent of the damage is, have them inspected by a tire professional.
Because of faster aging and weather cracking, some tire professionals recommend replacing RV tires when they are 6 years old, especially if the RV isn’t used that much.
Determining tire age: read sidewalls
How can you tell how old the tires are? All tires manufactured in the United States have a DOT number. The DOT number may be on the inside or outside sidewall. At the end of the DOT number the last three or four digits identify how old the tire is. Older tires used three digits. The first two identify the week of the year the tire was built, and the third identifies the year.
Newer tires use four digits. For example, 3208 would be the 32nd week of the year, and 08 is the year 2008. If you question the age of your tires, especially on a used motorhome, and you can’t find the DOT number, have them inspected by a qualified tire center.
Even though many other factors affect the life of your RV tires, you can see that the age of the tires is one of the most important considerations.
How to extend tire life
Now that we know how age and the elements can affect the life of your motorhome tires, what can you do to help extend the life of tires when they’re not being used?
Considering where and how your motorhome is being stored can add life to your tires. Of course, a covered, dry garage is the best scenario, but we know this isn’t always possible.
1. The first step is to clean the tires. Clean the tires with a mild soap and water. Avoid using tire dressings. Sidewall rubber contains antioxidants and anti-ozones that are designed to work their way to the surface of the rubber and help protect the tires. Washing tires excessively removes these protective compounds and can age tires prematurely. The same is true of many tire dressings designed to make your tires shine.
2. Inflate the tires to the manufacturer’s recommended inflation pressure when in storage.
3. Avoid storing tires on petroleum-based products such as asphalt and other heat-absorbing surfaces, and avoid storing tires on frozen ground.
4. If stored outside you should place some type of barrier between the tire and the ground surface. Make sure the blocking is wider than the tires’ tread and longer than the tires’ footprint. If the tires are not blocked properly and the load is not distributed evenly, the tire sidewalls can be damaged.
5. Avoid any exposure to heat and sunlight. If the RV is stored outside, cover the tires with covers that block out the sun.
6. The motorhome should be stored with the least amount of weight on the tires as possible. That means it should be unloaded prior to storage.
7. You should move the motorhome every few months to help prevent sidewall cracking from the tire sitting in one position for too long.
Following these simple tire storage tips can add life to your RV tires, but keep in mind that tire age and exposure to the elements are leading causes for tire failure. Make sure you know the age of your motorhome and automobile tires and always inspect your tires for signs of weather cracking before each trip.
|RV expert Mark Polk owns RV Education 101, a North Carolina-based company that produces and sells educational videos, DVDs and E-books on how to use RVs. Mark has more than 30 years of experience in RV maintenance. He retired from the U.S. Army in 1996 as a Chief Warrant Officer Three, specializing in wheeled and track vehicle fleet maintenance operations. He and his wife, Dawn, started RV Education 101 in 1999. They travel with their two boys in a 35-foot Type A motorhome.