My Fifth-Wheel RV

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Tires and Brakes

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Fifth-wheels throw off substandard tires quicker than a wild bronc will throw off a rider! Few things about your RV are more important that the set of tires you have on your rig. For the first few years after we got our fifth-wheel we experienced blowout after blowout. I was pretty sure the tires were in good shape and the pressure was correct, but I couldn't figure out why it kept happening. Finally, I figured out that the tires I was using just were not up to the weight I was pulling.

I won't pretend to be a tire expert, but experience has taught me a few valuable lessons. One of the most important is: Get the best possible tires for your RV. And don't skimp on the price - you will be sorry later.

Be aware that under normal circumstances, the tires that come with a newly purchased RV will likely be cheapo crap. My advice is to either negotiate for better tires or have them changed as soon as possible. The info contained here should help you become better informed as to what to look for and what precautions to take.

The info contained here is rather specific to fifth-wheels, although some items would apply no matter what type of rig you have.

Trailer tire characteristics

Passenger tires require different characteristics than trailer tires. Because tow vehicles are pullers, they require both traction and stability. As a result, tire tread is an important factor. Ride comfort is another. Trailer tires, on the other hand, only require that they stand up to heavy loads.

Here are some reasons that trailer tires can fail:

  • Heavy loads exceed tire rating. Do you weigh your rig at truckstops?
  • Speeds exceeding tire rating.
  • Under or over inflation. Do you have a monitoring system?
  • Improper weight distribution in the RV.
  • Tire damage such as cuts, gashes or punctures.
  • Rolling over obstacles such as curbs, rocks or potholes.
  • Excess exposure to heat or sunlight. Do you have tire covers?
  • Cheaply made wheels.
  • Age of the tires.
  • Crappy tires to begin with.
Click here for a really good writeup on trailer tire characteristics, by someone much smarter than me regarding all things trailer tires. The article is a little old (2012) so it doesn't talk about the new Goodyear Endurance tires, for example, but most of the info still obtains. Pay particular attention to his discussion about Chinese made tires.

-- Endurance speed rating
-- G-rated and up, wheel spacing
-- tire codes - most people confused..

ST vs LT tires

First-time trailer tire buyers are often confused by terminology like 'ST' and 'LT'. The term 'ST' stands for Special Trailer, and 'LT' stands for Light Truck. They are important distinctions for two very different used.

LT tires are not suitable for use on an RV, especially one that carries a substantial amount of weight. LT tires are meant for passenger trucks, with an emphasis on comfort. This is why their sidewalls are allowed to flex somewhat, to cushion the bumps and ruts of road travel. Thus, they do not have the kind of thick sidewalls that allow for greater loads found on fifth-wheels. Their flexible sidewalls also allow a trailer to sway back and forth, which is definitely a no-no for highway travel.

ST tires are constructed with sturdier materials and have sidewalls which can take heavier weights. They are specifically made for use on trailers, especially RVs.

ST, which stands for "special trailer" are the only tires recommended for fifth-wheels -- don't try to skimp by using auto tires or LT (light truck) tires; you will live (hopefully!) to regret it.

Most ST tires are made in China. Avoid these at all costs. Goodyear used to make a pretty good ST under the Marathon brand, but when they started making them in China they became substandard. Seems they learned their lesson, and have started making their ST tires in the USA now, under the Endurance brand. The ones we have on our 37' fifth-wheel are rated at 80 psi and 80 mph, although we don't try to push it that high except for passing. They are also high-load rated, but match them to your particular trailer loaded weight (GVW).

While you might be able to get away with it on a mini or lite trailer, DO NOT try to put LT tires on a large fifth-wheel! They are not made to support the weight; that's why they are called "light truck." While they may be cheaper than ST tires, you will wind up being sorry when your 14,000 lb fifth-wheel quickly shreds your LT tires to pieces. And even if you might be able to get away with it, I don't recommend trying; you will be taking a big chance.

Here's my horror story. As I said earlier, after we got our rig we had several blowouts on a single trip up to North Carolina. It didn't take too much research to see that the dealer tires that came with the trailer were substandard. I came to find out later that this was not a situatiion unique to me. So I looked around and found that the Goodyear Marathon tires were supposedly the best available at the time, so I had the tires replaced with them. Things got better and we didn't experience tire problems for several years. When the tires got old I did more research, and to my amazement found that the Marathons are now made in China. That was a show stopper for me, so I went to a large tire dealer in my area that caters to semis and other big rigs. I won't mention their name, but I got a set of ST tires from them with insistance that they not be made in China. After their reassurance, I took them back to the trailer and was agasp to see that, right on the sides they said "Made in China." Of course, I took them back, and then went to another dealer and got their "best" tires. Again, I got back and again, "Made in China." So, after taking them back I got onto old faithful Google and did a lot of research. I discovered that around the beginning of 2018 Goodyear started making their Endurance radial ST tires in America, and that they came highly recommended on the web. So I put them on and am pleased to report that after our 15,000 mile trip exposing them to the continuous mistreatment by the roads of the Canadian Maritimes, there were absolutely no incidents! I'm going to replace them before we go out West in 2019 because I'm not one to take chances any more.

Note that there may be other great trailer tires that came on the market since I did my research. Before you buy, do as much looking around on the web as you can. Remember the adage - "Google is your friend."

Tire codes

-- Endurance STxxx/65R16
Tire grades

Tire pressure

-- inflating over recommended max PSI does not increase load capacity
-- check pressure often -- cold vs hot
-- tire pressure monitors
-- heavy duty rims
-- tire gauges
-- inflator
-- compressor, jack

DO NOT over- or under-inflate your tires. They will experience wear a lot faster, and consequently be more prone to blow-outs.

Travel speeds

Lug nut torque

-- use compressor, lug wrench not enough
-- know specs

Roadside assistance

Having learned the hard way that trailer tire blowouts occur at the worst possible place and time, I decided to take matters into my own hands.

Our first action was to look into the Good Sam Roadside Assistance program. At first it seemed too good to be true but we decided to give it a try anyway. It turns out to be a pretty good service. The first time we used it was on the Florida Turnpike. They came out about an hour after we called them, changed the spare, and left with no charge. The second time we used them, the response time was about the same but we had two damaged tires. We must have ran over something but I never figured it out. Anyway, since I only had the one spare we had to call a local tire store to have someone come bring us a second tire. It turned out to be very expensive, mostly because the tire company had us over a barrel. Of course, this was not the fault of Good Sam. BTW we're also lifetime Good Sam member.

Our roadside assistance experience has been positive and we have continued to maintain our account with them. I'm not sure but I think they operate throughout the USA but I wouldn't count on them being available in Canada. You might also want to look into AAA or other comparable services.

The other thing I do is take a compressor and generator with me on all trips. Both are small enough to fit into my truck bed tool box, but are sufficiently powerful to meet my needs.

My compressor is a Porter-Cable that I got from Amazon, since I wasn't satisfied with what Lowes and Home Depot had to offer. The actual specs are

  • Model C202 Type 8
  • 150 psi
  • 2.6 SCFM [Standard Cubic Feet Per Minute] @ 90 psi
  • 6 gal
  • 120V / 60HZ / lPH / 10A

This compressor is powerful enough to raise the trailer so I change change tires, but it takes a few minutes to build up sufficient compression. I don't personally find this to be a problem, as a more powerful unit would probably not fit into my truck box.

I also have sufficient accessories to operate the unit. This includes a long pneumatic hose, a pneumatic torque wrench to loosen and tighten the lug nuts, a pressure gauge and an air filler attachment. I also carry a pneumatic nail gun and nails for unexpected repairs, especially if I plan to be "in the wild."

Of course a compressor isn't going to do much good if it can't be powered; hence, the generator. Mine is a Champion 100263 - 3100 Watt Dual Fuel Inverter Generator w/ RV Outlet (CARB). I was particularly attracted to this unit for two reasons. First, it was small enough to fit into the truck box, although just barely. The second reason is that it operates on both gas and propane. I find the propane option particularly nice in case I'm on the open road without gas [my truck uses diesel]. It also gives me options when boondocking.

  • 12 v starter with recoil
  • 192 cc
  • 95.7 lbs
  • 25.2" l x 17.3" w x 18.3" h
  • 3100 watts
  • 30 amp RV outlet
  • 12 A dc cig outlet
  • 120 v wall-type outlet; 2-pin w/ground
  • gasoline, LP
  • 1.6 gallon tank
  • battery included
  • 3 year warranty

Here is a web link.

With this setup I can (a) use the compressor at a campground to top off the tires or do other odd jobs, (b) use the generator when dry camping, and (c) use the combo to change tires on the road.

By the way, should you decide to get a compressor and/or generator, be sure they will both fit into your truck bed box before you order. Note that most pusher rigs already come with a built-in generator.

Trailer Brakes

-- umbilical cord
-- heavy duty?

-- lug nut torque
-- pack wheel bearings, once a year or every 10,000 miles - see here.

-- pop off dust cap from wheel. look for grease seal leakage. use grease designed for long use.
-- also good idea disassemble and inspect bearings and seals - some manufactures models are subject to premature failure.

Pull into a truck stop that has scales and weigh both your truck and trailer. A good scale will tell you the axle weight for the trailer, and also your tongue and axle weights for the truck.

If you have a large trailer, say over 35', consider getting G-rated or higher tires. But be sure that if you have two or more axles on the trailer, they are spaced wide enough to allow for the larger diameter tires.

-- good tires can make all the difference..
-- tire covers needed for pushers since tires are expensive

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