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Life in the back of a truck (part 3)

March 14th, 2009

This is part of an ongoing series on what it’s like to live in a truck camper fulltime. You may read other articles here:

  1. Part One – The fulltime lifestyle
  2. Part Two – Why a truck camper?
  3. Part Three – Weights & Dealing with them
  4. Part Four – Boondocking resource conservation

We still haven’t got the shiny pictures from Carlsbad uploaded, so I’ll go back to an old standby and bore you all with life in the back of a truck… again!

It’s a truck, you can carry anything, right?

Unfortunately, this is not the case. Weight is a big concern for most fulltimers, but I think it is a much higher priority for truck campers. At first glance, you might think a class C would be heavier than a truck camper, and you’d probably be right… at least until you add the truck. They’re on similar sized chassis, so why would you worry about weight so much more in a truck camper? If you stop and think about the construction differences, I think you’ll get a pretty good idea of what causes the problem.

Class C’s are built on a bare chassis as a stand alone unit. A truck camper is separate from the truck and still needs to maintain structural integrity. Additionally, it’s sitting on a truck that hasn’t been gutted by the manufacturer to remove unneccessary (for camping) features. A truck camper and truck combo has a fair bit of redundant construction compared to a class A/B/C RV. The camper has to hold itself together both on and off the truck, which is more than you would ask of a standalone RV.

But, it’s still way smaller than the giant 5th wheels and trailers you see people towing, right? Sure, but there’s a big difference in the way the weight is carried. Trailers put the bulk of the weight on their own axles, which is why trucks can tow so much more than they can haul. Trucks have all sorts of weight ratings including GVWR, GCWR, GAWR, and tire load ranges.

Confused yet? Ok, let’s see if we can make some sense of these ratings and which ones will matter to you.

GVWR is Gross Vehicle Weight Rating. It is the total combined capacity of the vehicle including cargo, passengers, fuel and tongue weight.

GCWR is the Gross Combined Weight Rating. This is the amount the vehicle is rated at including any trailer it may be towing in addition to passengers, fuel and cargo.

GAWR is the Gross Axle Weight Rating. This is the combined amount of load that can be carried by each axle. You may run across different ratings for front and rear axles. Truck campers are typically engineered so that the center of gravity is directly above the rear axle, placing the bulk of the camper’s weight above a single axle.

Tire Load Ranges are the amount of weight each individual tire can carry. Ideally, this could be multiplied by the number of tires on an axle and used in a similar manner to GAWR, but I would recommend subtracting a safety margin to account for unequal loading or any other event that could increase load on one side of the vehicle such as cornering.

So what do I care about all these numbers? How about some practical advice?

I suppose the best advice would be to buy a truck that far exceeds your expected camper weight including water, propane and all the things you can’t live without. Unfortunately, it’s often hard to know what these numbers are ahead of time. No matter what, the odds are you’re camper and gear is going to be heavier than you expected if you tried to figure it out based on the manufacturer’s claims and your own estimates of what you’ll bring along.

If you’re buying a new truck to fit your camper, you’ve got a leg up in the process here. Buy the appropriate sized truck and do yourself a favor: order it with the camper package which includes more leaf springs! If you’re like the rest of us and shopping for a used truck or already own a truck, there are a few things you can do.

First of all, be aware of the camper’s weight everytime you look at one. Know how much your truck is rated at and try not to exceed it. There are a lot of overweight rigs on the road and doing just fine, but the more overweight your combination, the more work you’re going to have to do to keep it safe.

The most important weight rating, to my mind, is the tire load range. Exceeding this increases the risk of blowouts at highway speed, which can be disastrous. You may be able to get away with being over your GVWR and GCWR a bit without much trouble, but please don’t try and skimp on tires or exceed your axle rating. Fortunately, it’s pretty hard to overload a dually with load range E tires. If you’re looking at a heavy camper on a 3/4 ton truck though, don’t skimp on your tires even if it means you need to shell out for load range F tires and accompanying wheels.

What can I do to make this camper handle better?

So, you’ve got a big heavy camper, and your truck didn’t come with the camper package spring pack? Odds are good it’s going to wobble all over the place going down the road. It’ll be top heavy, leaning and swaying with every minor curve. You’re going to have to beef up that suspension one way or another. There are a lot of different opinions on just how to handle it.

For fulltiming, I’d recommend taking the truck into a good spring shop with the camper on and let them fix you up. Depending on the shop, you can get a couple of leaves added for $400-700. A good shop is going to make sure you’re level side to side as well, which helps if you’ve got a slide on the camper making one side much heavier than the other.

If you just want the camper for vacations, Timbrens might be a better idea. The cost is low and you can bolt them on yourself in a few minutes. They are basically a rubber spring that forces your overloads to engage sooner. I was pretty happy with the results for several months, but the constant load of hauling a camper eventually compressed the factory springs to the point where the Timbrens were taking excess weight and transferring them to the overloads. Eventually, we broke an overload platform as well as rupturing a Timbren. The company is excellent to deal with, however. They shipped us a replacement set no questions asked.

I haven’t tried airbags or supersprings on a truck camper, so it would be unfair to say too much, but I have seen airbags fail, in pretty messy ways in different applications. When the cost of either product is similiar to that of having a spring shop install extra leaves, I prefer the big chunks of metal professionally installed in the same manner as the factory suspension to a fancy addon that I may have to spend a day or two working on.

Are you ever going to stop?

Ah, there’s one last important thing to consider when you’re close to or maybe a hair over your GVWR even if you’ve got a rock solid suspension and good tires. Just how are you going to stop 6 or 7 tons of steel and flammable substances hurtling down the road?

First of all, drive like you’ve got some sense. Remember in driver’s ed where they gave you all those rules of thumb to follow regarding your speed, safe following distances and how long it would take to stop? Double all the distances. Maybe even try driving the speed limit instead of 10 over for a change. Tailgating in a truck camper is just stupid. You’re on vacation, why not relax while you’re on the road too?

Mountains are a good thing to discuss. A lot of people haven’t hauled much weight through the mountains and don’t understand just how dangerous it can be if you don’t drive sensibly. When you see signs like ‘truckers use low gear ahead’ or grade warnings for the next 10 miles, pay attention. You might not be pulling as much weight as the 18 wheeler in front of you, but you may be more top heavy and definitely have less brakes than he does.

One of the old rules of thumb is to come down a hill in the same gear you went up it. This means if you had a hard time getting up the mountain and were chugging along at 25-30 mph, you should probably downshift when you start down and let your engine do some of the work to keep you at a safe speed. If the RPMs or speed starts getting too high, brake firmly and knock a good chunk off your speed. Riding the brakes to try and maintain a constant speed is a good way to overheat them. Get those brakes too hot and you might find you don’t have them when you need them. Many times, you can engine brake down a steep mountain and not use your brakes at all if you keep the speed low enough to begin with.

If it’s time to replace your brakes, think about upgrading to shoes and pads with more stopping power. They might squeak a lot more and cost a bit extra, but they will give you a lot more room for error if sensible driving isn’t enough some day.

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One Response to “Life in the back of a truck (part 3)”

  1. Blue says:

    Very good information here, I especially like your advise on tires and springs. I just started to truck camp and after reading some of the forums as to what I should be doing I became somewhat disenchanted with what was written about setting up the truck.
    Some of the descriptions of what they had on their trucks read as if they were preparing to launch themselves by rocket into outer space instead of just setting up a truck to carry a camper.
    My tires are “E” rated and an extra leaf was added to the springs of my f250, the tie downs were fabricated in my shop, The truck and camper sit level and I did make a few week end camping trips which turned out just fine.
    I intend to custom fit an extra water tank in front of the wheel well on one side and fabricate a box for an extra battery on the other side.
    The camper is a ’95 coachman.
    I enjoy reading your website, your common sense approach to tc camping is like a breath of fresh air. As I have indicated above, it seems as though some folks are just trying to outdo each other in setting up their rigs and are really only confusing the new folks just starting to tc camp of course safey is a primay factor however some folks just over do it.

    Keep up the good work and keep us informed


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