Original post date.
Oct 31 2006, 04:57 PM Post #1


Gentlemen.

.....When you step into a vehicle or tow a trailer you are putting 100% faith in your tires. With this in mind, how well do you know them?

.....In other words, how often have you checked the pressure? How often have you spun them and looked for irregular wear, nails, or other signs of possible problems? Tires do a great job of holding their air pressure against a clean surface like the rim. They can also hold their air pressure for some time with a nail puncturing the tire. Only to eventually slowly leak and possibly blow out at speed as the heat increases with the loss of pressure. This is one of the many issues I deal with on a daily basis.

.....Here is a list of things we should do and not do regularly.

1). Determine your proper air pressure.

The number one challenge/goal of a tire is to dissipate heat. Proper air pressure & load will ensure that to it's maximum effectiveness. We all know that a low tire will wear prematurely on the outsides of BOTH edges (shoulders). It will run hotter and also contribute to the possibility of blowing out. Over inflation will cause the tire to wear in the center of the tread. Both of these issues will also offer less traction as the contact patch will be smaller than with the correct Psi. This can effect braking, and drivability in adverse conditions like high winds, water, sand etc.

So where should you set your air pressure at? First things first! We'll start with the trailer or 5th wheel. You need to know what your trailer weighs completely loaded. Don't just read the often inaccurate information on the unit's ID tag or sticker. Weigh the thing! There are scales at the AM/PM at the 186/111 split on the way to Glamis and Ocotillo. Many of you will be surprised as to how much weight you are towing.

Most people ONLY read the psi number on the side of the tire. They don't take into account that the information is for that particular tire's heaviest load capacity. For instance. I get people all the time in my shop with say... an F250 and Load Range "E" tires. They tell my guys to set the psi at 80? Sure enough he has already warn through 1/2 of the center's tread and the shoulders look brand new. He forgot to read that 80psi is recommended for that tire with it's labeled max load capacity sitting on the tire. So NEVER just read the number on the side and go from there. That's why we need to know what we are dealing with in applicable weight factors before we determine the proper pressure..

If your trailer/5th wheel weighs 10,000 lbs. that doesn't mean you have 5k on each side of the trailer, or 2500 lbs on each of the 4 tires (if it's a double axle) . You must also consider the tongue and pin weight. It is very possible with a trailer that over 1000lbs.or more could be resting on your hitch, and 2000 or more in the bed of your tow rig with a 5th wheel. So determine that first. (remember with the unit fully loaded).
So in this case, and to keep it simple, lets say that out of the 10000lbs of this trailer 1000lbs. are on the hitch. That leaves you with 9000 on the tires. Let's say that it came with ST225/75R/15 trailer tires. Usually this size will have a load cap of 2540per tire at max pressure of 65psi. That's a total of 10,160lbs on the tires. Since 1000lbs.of that is on the hitch you are within the limits at 9,160lbs. Even though it's close, in my opinion, you are more than safe. What will have the most effect on the tires holding up is PROPER MAINTENANCE AND REGULAR INSPECTIONS.

Let's talk about the 5th wheel. If you tow a 35' 5th wheel with 4 full size quads, 100 gal of water, clothes, food and everything for a family of four. You're going to weigh in some where around 14K. As a guess I'll say 2200 will be on the pin. Let's pretend that this is a newer model who are all going to triple axles & ST225/75/R15 load range "D" tires. With the 2540 load cap x 6 that gives you a max of 15,240lbs Minus the 2200 that's resting on the bed of your truck you would be at 13,040lbs. or 2173.33lbs each tire. If you are not at your max how do you determine the proper pressure? I use percentages. In this case I'd still run max pressure. But if your trailer or 5th wheel is much lighter than the load cap on the tires you would use this method to figure it out. If the weight of your trailer is 50% of the tire's capacity then you would inflate it to 50% of the max psi. Unless the percentage equals less than 40psi per tire.

Set your tire pressure when it's dead cold in the morning. That's why the tire says 65psi COLD. If you actually put a gauge on the tire when you are filling up for gas after towing for two hours in 80 degree temps you will get a higher reading than when you topped them off at 7am in the cooler morning air. Sometimes as much as ten lbs higher. Leave it alone. Don't reduce the air pressure! The tire manufactures account for that. Reducing the pressure will increase it's running temps and could contribute to a blow out.

2). Sharp U-Turns, and jack knifing when parking etc. can cause the tire to become stressed to the point where the belts separate. Then air will leak in between the belts and cause a bubble or high spot.

3). Any substance applied to the outsides of a tire to enhance it's look, or even claming to protect it will shorten the materials life. It's like rubbing baby oil on your arm and holding it out in the sun all day for weeks on end.

4). LT vs. ST? Light truck tires and Special trailer tires are not created equally. Although some people run light truck tires to achieve a heavier load capacity, or an M+S rating, the sidewalls are much thinner vs. trailer tires. Light truck tires are designed to carry loads and provide ride comfort so the sidewalls are thinner. Trailer tires are not built for ride comfort and routinely are much thicker at the sidewall. I myself , and many people I know have run light truck tires on our trailers. You can get away with it. But be aware that due to the issues with the side walls you can experience abnormal towing characteristics such as "wagging" or "pitching". Be careful.

5). Do you have a jack? Do you have the key to the spare lock? Do you have the proper size socket & wrench? I can't tell you how often people come in on a tow truck because they didn't have one of these things in the vehicle or trailer. Check it all out.

6). You need two things when it comes to tires. Tread depth, and casing integrity. "But there's still 90% of the tread left". I hear that all the time from RV and trailer owners. Yet, I can stick my finger nail in the sidewall cracks that are 1/4" deep. If the tire material has broken down to the point where it's coming apart under the pressure of it's own inflation., think of the amount of added force spinning it at 60MPH will have. Only partially true is the ad that states, "You have a lot riding on your tires". . We don't have a lot riding on them. We have EVERYTHING riding on them. Be smart. Spend the money on new tires. There is no such thing as a determined shelf life. Some people say change them after so many years. I know. But the only way to be sure what you have left is constant attention.

7). Again, check your tire pressure before you leave, during, and when you leave to return home from your trips. I check them with a gauge before we leave. I then take a close look at them when I am fueling up. Usually at the pump there is a nice flat surface to see the bottom of the tire at the side wall.. If one looks like it's budging more than the rest I grab the gauge. Then before I leave to return home I re-check them all with a gauge and repeat the gas station method until we arrive home. If you pick up a nail while you are on the road you will see it's effects before it's too late in most cases. With tires trailing so close to each other they are more susceptible to punctures than just your everyday 4 wheeled vehicle.. Why? It's simple really. The front axle tire will hit an object like a nail and pop it up just right for the trailing tire to pinch it between the road and the rubber forcing it through the tire.

Not only can YOU prevent forest fires.
But YOU can also prevent many tire problems before they have a chance of ruining your day.

OK, have I missed anything?

thanks for food for thought. i appreciate it.

Very good information. Thanks

Makes perfect sense to me.. Even though we had a blow out (more than likely a puncture and failure, but age might have been a cause as well) and flat last trip (stay off the dirt next to the road, that's twice I have gotten a flat driving off the road into the dirt!). 5 load range D, (instead of C's) tires and $600 less in my pocket, I feel real good about the purchase..

I feel for the people that have had multiple blowouts.. It sucks.. Luckly we only had 1 in 5 plus years of TH life.

GREAT reminder!!!

The only thing that i do you didnt mention was check em at every stop. I dont put a gauge on em or anything like that, but if im stoping somewhere for some reason (gas, food, whatever), i will do a walk around the whole trailer and see if anything looks funny and take a good look at the tires. Your so right, a nail in the tire will hold plenty of air, but dosent help the integrety at all!

I'm ready for those stone wheels like in the Flintstones.

Great info, thanks.

You mean this part?
7). Again, check your tire pressure before you leave, during, and when you leave to return home from your trips. I check them with a gauge before we leave. I then take a close look at them when I am fueling up. Usually at the pump there is a nice flat surface to see the bottom of the tire at the side wall.. If one looks like it's budging more than the rest I grab the gauge. Then before I leave to return home I re-check them all with a gauge and repeat the gas station method until we arrive home. If you pick up a nail while you are on the road you will see it's effects before it's too late in most cases

LOL.

Tire pressures were checked the morning before the trip. I did a walk around the trailer before we left that evening (checking lights and tires). 2 1/2 hours later, boom! Tread seperated from casing and wrapped around axle.. My only real guess is age, trailer is 3 years old, and no telling how long WW had the tires lying around, since I had to get a replacement right after getting the trailer and being told General is not making trailer tires anymore.

^^^^^^^^^^^^

Great tips! Any suggestions about storage. We are going to store our trailer in a dirt lot, would parking on plywood help?

TTTA

Huh?

To The Top Again

I always wondered what TTT was.

Thanks!

Anybody have any ideas reccomendations about parking in dirt for storage?

The best way to store them is on jackstands. I realize this is not realistic for most. But it keeps them from slowly deflating, developing "high spots" etc. Other than that keep the sun off them is the most important..

In one of the local storage area the trailers are parked heading east and rear towards the west. So the right side of all the trailer and motorhome tires get baked all day while the left side tires do not. All the time I have customers bring in two rims with cracked tires from the right side. The dry/wet and hot/cold variations do effect tire life somewhat. But the biggest problem is just the sun exposure.

The best way possible is to block the sun is with some type of apparatus that allows the tire to breathe. For instance if you use a piece of ply wood see if you can get it to work without leaning it up against the tire. The part of the wood that makes contact with the rubber will cook that spot. Also while those neat tight fitting drawstring/elastic tire covers sure look nice they can trap heat and increse the temp inside the cover extremely depending upon exposure. The only thing I wanna cook in a bag is my Thanksgiving turkey!

I am making covers out of plywood with an "L" bracket at the bottm to slide under the tire ( After jacking it up or pulling forward onto it) thereby keeping the cover from blowing away (cause I live in the H-desert) and keep it from touching the tire itself. Painting them gloss white will deflect a lot of heat. When I get them done I'll post some pics.

Peace guys,
Hope this helps.