Most of us can look at tire that is worn out from miles and tell by the tread that it needs to be replaced. For your RV, that is almost never the case though.
Why? Almost all RV tires ‘age out’ before they are worn out due to tread. As the tire gets older multiple factors can cause tire failure. Tire Dealers like Les Schwab limit the age of the tire they are willing to repair or maintain citing safety concerns. Having worked on a truck tire replacement machine myself when I was younger I clearly remember a tire ‘blowing out’ on me and knocking me on my butt, their concerns are valid and also admittedly a little self-serving.
Tire ‘experts’ and manufacturers all state that most tires are un-roadworthy at some point between 5 and 10 years old.
So what happens to my RV tire when the RV is just sitting and 7 years later the tire still looks like new, I don’t need to replace them right? The answer is – maybe.
If your trailer is in a treed or shaded are in the PNW and the tires are properly inflated ( check the PSI when parked annually at minimum) and you aren’t going on a trip – I wouldn’t recommend replacement. In most other scenarios I would and here is why.
*Tires that have been left underinflated for longer periods of time suffer sidewall fatigue. This means the tire is much more likely to fail even after re-inflating.
* Tires fail much more often when they heat up. That means the same tire that can handle the stress of highway travel in the AM at 60F is more than twice as likely to fail in the afternoon when the pavement is 90F.
*Underinflated tires over-stress the sidewall as the tire has to ‘marshmallow’ or squish (flexing the sidewall) while traveling. Most all tires traveling 60mph at 75% recommended load being underinflated 25 psi will fail due to heat buildup in the tire.
*Tires showing minor cracking in the sidewall are more prone to tire failure. Tire sidewalls showing cracking indicate the sidewall is less flexible. Some tire manufacturers have produced RV tires that have sidewall cracking at less than 2 years on the road. (Thanks Michelin) it has been suggested that this is intentional by many ‘experts’. The tire manufacturer will say its within specs and not warranty it and the tire shop will scare you into a new set of tires.
*Tire failure has resulted in many accidents, some total losses and some fatalities. We had an insurance job in 2019 of a class C motorhome with a rear dual tire failure resulting in $20,000 damage to the RV and six months out of service.
All this is great info, but what should I do to make sure we are safe?
1) Know the build date of your tire. Every tire will have an oval shaped tattoo about the width of the tire near the bead with a 4 digit number. ( see picture) This number is very easy to decode. The first two digits of the code is the year MFG, the second two digits are the week (01-52) If your code is 1451 it means it was built in 2014 about Christmas time.
2) Know your risk factors. If your tires are rated for twice the weight they are carrying I am much less concerned about healthy looking tire that is 7-8 years old than one that is rated for 1750# (std 3500 trailer axle) with a tandem axle trailer that weighs 6500# and is full of gear likely having that tire at 95-110% of rated capacity.
3) Visually inspect both sides of the tires annually if the RV has been driven. Potholes, curbs, road debris, rocks and such can bruise the sidewall of the tire. Sometimes there is visible damage sometimes there isn’t. If you feel your tires have an impact there is a real chance of damage. No tire is immune from sidewall damage, generally the better tires have stronger sidewalls.
4) Check your inflation before each trip. If you have a Class A or a large Fifth Wheel your home, service station coin op, or 12V compressor is not going to help. Visit a real tire store or dealer equipped to handle pressures of 80psi+.
5) If your tire has a blister, bubble, has a sidewall crack you can stick the head of a ballpoint pen into or cracks most of the way around the bead, it is done. Do not exceed 35MPH on the way to the tire dealer.
6) If your tires are worn significantly more one edge, loading or other issues exist rotate or replace the tire immediately. Have your axle bearings serviced! If it continues seek professional help.
Tires aren’t cheap, but they are less to replace than the damage they cause when they come apart. Ryan’s RV now installs a tire sealant to prevent under inflation and will prevent almost all premature tire failure and flats due to tread punctures.
Axle bearing service is also an important part of Trailer ownership and can affect tire wear. Axle service should be done once every 7500 miles with annual inspection.
Credit Kelly Klopfenstein, 30 Year RV Professional, Ryan’s RV Inc.