Winter is coming and you are about to park your RV or trailer till spring. One of most important considerations is to protect the tires. Here are few tips to make sure tires don’t deteriorate and will be ready to roll safely next spring.
When parking an RV for an extended period, make sure its is as level as possible to prevent overloading one or more tires due to weight transfer. If your RV or trailer does not have built-in leveling devices, use blocks for leveling.
Place something substantial such as a wooden plank under each tire so it is not in direct contact with bare ground. Make sure the tires are fully supported when using blocks. The load on the tire must be evenly distributed on the block and, in the case of duals, evenly distributed on blocks for both tires (see drawing). This will prevent premature sidewall fatigue and ultimate tire failure. Better yet place blocks or jack stands under the axles so that tires carry no load while in storage.
On many RVs and trailers, tires do not wear out. They deteriorate because of the ravages of the environment while sitting motionless for months exposed to the elements. For instance, the biggest causes of deterioration are natural aging as well as ultraviolet and ozone damage. You might ask why this is not a problem with a vehicle you drive daily. For cars and trucks driven frequently, oils in the tires come to the surface during flexing and protect the rubber from ultraviolet light and hardening. Also when left idle, natural aging may cause the rubber to crack prematurely, especially in the sidewall area. Both UV and ozone damage can be greatly slowed down by storing tires inside, or under, an opaque, waterproof covering so they are shielded from direct sunlight.
If you remove the wheels and tires, store them in an area that is clean, cool, dry, dark and well ventilated with circulating air. Tires should not be stacked so the tires at the bottom of a stack lose their shape.
Before that first trip next spring, carefully inspect tires check both inside and outside sidewalls and tread area as well as the condition of valve stems, valve caps and wheels. The tread should be checked for any unusual wear, cracking, penetrations or cuts. An uneven wear pattern can indicate misalignment or worn suspension parts requiring correction. If tires show cracking in the sidewall or tread surfaces that are more than 2/32nds deep, they should be replaced.
Any tire that is over five years old should be especially carefully inspected for cracking and replaced, even if it has acceptable thread left. To determine the age of a tire, look at the DOT number on the sidewall, which identifies the manufacturer, plant where the tire was built, the type of construction, and the date of manufacture. For example, the number 245 (i.e. DOT8ST46245) indicates the tire was manufactured in the 24th week of 1985 or 1995. A triangle symbol denotes the decade, that is the 80s or 90s. More recently produced tires use a four number code, for instance, ….3401 or the 34th week of 2001. Also check the age when buying new tire. It is possible that a tire has sat in a dealer’s inventory for many years, especially if it is an uncommon size.
Finally, always check air pressure before and after storage using an accurate truck tire gauge. A multiple-angle airhead is needed on dual wheels. Pressure should be checked on cold tires - meaning the RV should not have been driven for more than about a mile at the time of testing. Do not reduce pressure when a tire is hot or exceed the maximum cold pressure. Note that there is often different recommended single and dual wheel inflation pressures.
The load a tire can carry depends on the air pressure. This information is molded into the sidewall of truck tires. On other tires, it is part of the tire designation on the tire, but you will have to use a load index chart to translate this into a pounds rating (see chart). The proper air pressure depends on the weight carried by each wheel. While you think you are operating under maximum capacity, you may be overloading one or more tires while the others are carrying less of the load. You should determine the weight carried by each tire by using a scale to weigh each axle, or better yet each wheel, separately.