Text Box: Home Page 

 


Truck Campers- Buying Basics Summary
I have observed many prospective new truck camper owners asking common questions at the NATCOA and Open Roads Forum , including myself in September 2003. Truck campers are a unique RV choice. They are the only land based RV without wheels; yet they can be fully self-contained and go virtually anywhere you can get a pick-up truck to go (within reason). Their popularity is rising as their amenities have come to equal anything you can find in other RV types. Visit the Truck Camper Topics of the Open Roads Forum and you’ll find your head swimming with options. I started a thread there with the intention to make the first time truck camper buyer aware of the basics. Interested people started suggesting more and more topics. I’ve broken that original thread up into more individual topics. I invite anyone who wishes to add more detail to each of my opening threads to do so.

If you already own another type of RV like a travel trailer, you will already have been exposed to some of this information, but what I’ve tried to concentrate on are the specifics of what makes buying a truck camper distinctive. (Note, please send me a PM if you see a revision that needs to be made and I will happily correct it) Here are thread topics discussing the items uniquely important for considerations when buying a truck camper:

 

Truck Campers- Overall Weight Basics
Most important consideration when buying a truck camper is weight. The camper you will carry will be determined in large part by the truck you intend to put it on. Most own their truck first (if you plan to buy a new truck and a new camper, determine the camper you want first). If you own your truck already first thing is to look at the Gross Vehicle Weight Ratio (GVWR) listed on the door edge of your truck. The GVWR is the maximum weight of you fully loaded truck. Next, you should have your truck weighed with a full tank of gas at a public scale (at truck stops, waste disposal sites, and some states allow you to use the highway scales to name a few). Subtract the weight of your truck at the scale from your trucks GVWR and that determines how much camper you can carry. For example, the typical ¾ ton truck will weigh about 6,200 lbs unloaded (depending on manufacturer and optional equipment). ¾ ton trucks usually have a GVWR of 8,800 lbs. The math is simple; 8,800 – 6,200 lbs means you would be able to carry a 2600 lb camper fully loaded with all gear, food, people, liquids and anything else.

The next most important thing to know is that when you go to a dealer's lot and you look at the weight information marked on a metal plate somewhere on the back of the camper, that weight is for the camper without options and without any thing loaded. A good rule of thumb for guessing how much that unit will weigh loaded for a weekend with all of the options you will want is to add 1000 to 1500 lbs to what you see. There are campers available in a wide range of weights, from small light campers that can go on a import compact pick-up to huge beasts of a camper with double slide outs that are better suited to go on heavy duty commercial trucks like the Ford F550. And in between is everything else. If you own the more common ¾ ton truck and you have found you can carry a 2600 lb camper, there are many campers available. When you go to the dealerships or to an RV show, a surprising majority of the salesmen and factory representatives will tell you your truck can carry much more than that. Don’t let them lead you into an unsafe condition. If you want a camper with more options than you can find for less than 2600 lbs loaded, the most ideal thing to do would be to buy a bigger truck. This is unrealistic for many people. Can the truck be modified to improve how it handles overloaded? In a word yes, but this will not change it’s GVWR, nothing can do that short of buying a new truck will increase a truck’s GVWR. Still many truck camper owners do drive with loads that exceed their GVWR. If you plan to be one of them, then please read the following topics to learn ways others typically do this.

 

At RV.net, others have added very good comments on the above:

 

Moss2940, “[The location of the camper’s weight sticker] varies with the manufacturer. Some I have seen the weight on the back is for the weight of the camper with options, nothing in the tanks, Host comes to mind. It has been a while since I actually read it but I remember the Lance tag is for full fresh water and propane tanks, no options. I am sure there are other variations. Probably the best advice is read the tag and see what it say's.”

 

 

Truck Campers- Stepping Beyond Weight Basics
Now the subtleties begin. You may weigh your truck as described above, but in the glove box you find a sticker from the manufacturer that says the limit for a slide in camper is only 1850 lbs, so what gives? Why did weighing the camper determine that you should be able to carry a 2600 lb camper? The glove box sticker is usually assuming that your truck has all seats filled with 150 lb adults. If you were alone when you had the truck weighed (and you weigh 150 lbs) the math would work out perfectly. You at 150lbs + gas = 2600, and 2600-(150 x 5 empty seats)= 1850 lbs. Clearly, who will be the passengers in your specific case will vary. Few people drive with all truck seats filled, so he glove box sticker is usually conservative by at least 300 lbs, that’s why going to a truck scale is important.

If you look at the signatures of the owners of campers in the Truck Camper Topics and you will see that least 80% of the truck & campers are not meet the GVWR of their trucks. Is this safe? 80% of drivers drive faster than the posted speed limit. This doesn’t mean driving fast is safe, it’s a measured risk, and the example of successfully overloaded trucks does not mean overloading is safe. What you should take note of is that of the overweight trucks, if you unloaded all of the campers to the basic model and then weighed the truck, you would probably be just within the GVWR. From my truck example above, if you decided to buy a camper that would ultimately put your truck over its GVWR loaded up, by the example of others, find a truck camper that lists its basic dry weight of 2600 lbs or less.

 

 

Truck Campers- Axle Weights
When you take your truck to a public scale, its important to not only get a weight for the total truck, but to also get a weight for each axle (the weight on the front tires and the rear tires). If you are going to be over the GVWR, you will really need to know what your truck’s allowable axle weights are. Even if you are within your truck’s GVWR fully loaded, you still need to know that the axle weights are not exceeded. In the same place you find the manufacturer’s GVWR on the truck, there will be a listing of the front and rear axle maximum weights. The typical ¾ ton truck will have a front axle allowable weight of around 4500 lbs, and the rear axle limit is usually 6084 lbs. Typically unloaded at the scale this truck will weigh 3600 lbs in front and 2600 lbs at the rear tires (notice they total the 6,200 lbs of total truck weight). On this truck, the maximum load on the rear axel would be 3,484 lbs. Whoa, your saying, why is it overall I’m only allowed 2600 lbs going by the GVWR and yet my rear axle can clearly take 3,400+ lbs? I can’t give you a clear answer to this, but if you’re wondering why 80% of all truck & camper combos travel thousands of miles without incident, the answer is partially here. For more about what limits a truck’s axle rating, read the section about tires.

 

 

Truck Campers- Tires
It’s no coincidence that any truck whose rear axle is listed to allow 6084 lbs maximum has tires that have a maximum load is 3042 lbs each stamped on the sidewall. The logic is simple, if each tire can only carry 3042 lbs each, combine them and that’s 6084, and tires are made of rubber so they are the most flexible and vulnerable part of the suspension system. Nearly all trucks have axles that can carry more than the stock tire ratings, but that information is very hard to find. What you will find however is that many truck campers will weigh more than 3400 lbs loaded and that the total weight on the rear axel will be more than 6084 lbs. Now you’re wondering how those overloaded campers get away with this. Simple, they’ve weighed their rig, determined that it’s overweight, and have done something about it Namely they buy tires and rims that are rated to carry the load they know they have. If in my example, if you have a 4000 lb loaded camper on a truck and the rear axel unloaded weighed 2600 lbs, then you’ve discovered that the rear axel weighs 6600 lbs with the camper on and loaded. What you need are tires and rims that are at least rated to carry that load. The next most common tire rating is 3415 lbs, which would make them capable of supporting 6,830 lbs, which is not much of a margin of error, but it’s better than being overweight. Tires are probably the weakest link in the suspension system. They are susceptible to load, changing air pressure, heat build up and they contact the road where hazards abound. It’s very important to have your truck and camper weighed to make sure your tires are rated to carry the load you are putting on them.

If you decide on changing your stock tire type, there are more things to consider than just the tire's load rating. ¾ and 1 ton trucks usually come with E rated tires, but not all E rated tires have the same load rating. This has to do with much more than tire size. The number of sidewall ply’s, the way the tires are made, tread type and other factors effect what load range can be stamped on the tire. The sizes can be confusing too; I know they are to me. Recently, most trucks have come with 16” diameter rims (Dodges have started coming with 17” rims on some models). But beyond the rim diameter, you must know the width of the rims on your truck. For example, stock Chevrolet 2500HD’s come with a 16”x6.5” rim. Most if not all tires rated for 3415 lbs on a 16” rim requires a 7” wide rim. When I discovered that my camper was too much weight for my stock tires, I immediately went to a larger tire size and ran it on the stock rims for a few thousand miles, but I never relaxed until I upgraded the rims to a wider rim that had the proper load rating stamped on them. For more information on tire sizes and choices on 16” rims use the search feature and type tires into the topic.

I have followed many inquiries for a 16” G rated tire and haven’t seen a true one yet. What is a popular alternative is to upgrade you tires and rims to 19.5” diameter rims. There are many more heavy load tire options in the 19.5” tire size. One big reason is that with the larger rim diameter, the sidewall is smaller and therefore flexes less. But, even though the sidewall is smaller, the overall diameter of the tire will be an inch or two more than your stock tires. This will affect your truck’s speedometer, odometer, ABS possibly, and rear end gear ratio to a small extent. Going to a larger load rated tire on your 16” rims will also probably change the overall diameter too, but not as much as the change in rim size. What you gain with 19.5” rims is a much larger load capacity and if you have an extremely heavy camper, this may be your only safe alternative short of buying a dually truck.

Dually truck owners must also know their tire ratings compared to their actual load. Even these trucks get overloaded and require upgrading stock tire sizes, but they have the added wrinkle of needing to watch for things like being sure the larger tires do not rub together under load.

As you can see, there are a lot of specific questions and considerations when upgrading your tires. Narrow down your choice between staying with your stock rim size, or if your pocketbook allows, upgrading to a larger rim size and then do searches on discussion threads here. There are people with far more tire knowledge than me posting here and they are the ones you need to read. Hopefully the info I’ve provided helps you narrow your focus some.

One other thing to consider when upgrading tires is to think about the valve stem.  Don’t make the mistake of upgrading your rims and tires without knowing if your Tire Installer is installing a valve stem that is rated for the same loads as the rest of the tire.

 

At RV.net, others have added very good comments on the above:

 

Reddog1, “To add to the wheel post, I was informed by a friend who was in the wheel business for over 20 years, that side loads measured wheel loads. He learned this from his brother who was a wheel designer for a major wheel manufacture for over 30 years.”

 

 

Truck Campers- Suspension Upgrades
O.K., you’re human. You want more camper than your truck’s GVWR says it can handle, and you can’t afford to replace your truck with a new one. What have other owners done? What they have done is like the tire example; they have taken steps to modify their trucks to handle the extra weight better. I am not advocating you overload your truck. I am simply relaying the same information available in countless threads on this forum.

After making sure you have tires that can handle the load, you need to help the factory-equipped springs. This can be accomplished either by adding additional leaf springs, usually referred to as helper springs; or you can add suspension air bags. Do NOT confuse suspension air bags with air shocks. Suspension air bags are connected between the truck frame and the truck axle directly. Air shocks are connected between the frame and the axle by a small pin that cannot carry the additional weight of a camper.


The advantage of helper springs is that they require no maintenance. Air bags adjust to the load by the amount of air pressure inside. This air pressure can be adjusted depending on your load conditions, and when the camper is off the truck, all of the air can be emptied to restore your ride to a softer condition. With either the helper springs or the air bags, you need to buy a product that is rated for the weight of your loaded axle (see Truck Campers- Axle Weights).

The shocks that came with your truck will undoubtedly not be up to the task of carrying a camper, overloaded or not. You will want to upgrade. There are two main approaches for shock absorber upgrades. Self-adjusting shocks change their dampening effect based on how much force is asserted every time they’re depressed. The other option is manually adjusted shock absorber where you change the shocks setting depending on the weight you put in your truck. The advantages of self-adjusting shocks are obvious, but the disadvantage is you cannot change them if you find they are not quite working well in the driving condition you experience. The advantage of the adjustable shock is that you can find the setting that works best for you; the disadvantage is that they are either adjusted at the shock itself, or require the installation of an expensive in cab adjusting system.

You may find that your truck sways from side to side too much with a camper on. All campers will make most trucks sway more than the truck does unloaded, but if the sway is excessive, you probably do not have an anti sway bar. This is a bar that connects to the axle near each tire and connects to the frame. When an extra load is applied to one tire, the twisting force in the anti sway bar pulls that load up and puts some force on the opposite tire. Aftermarket sway bars are available for most makes and models of trucks that did not come with them.

 

Truck Campers- Camper Options
You can buy nearly all of the same RV options for a truck camper that you can for the other RV types. Options unique to truck campers are worth discussing here. Camper jacks top my list of uniquely camper option items. You can buy manual jacks that require you to either pump each jack up and down like any other hydraulic jack, or you turn a crank. These are almost exclusively available only on smaller lighter campers these days. Most campers come with electric jacks. Most of these come with some sort of control that allows you to raise and lower the jacks by yourself. Most of these controls are remote, either wired or wireless, which allows you to walk around the rig while lowering or raising the camper. Wired remotes have that pesky coiled phone style cord to deal with, but the signal is constant. Wireless remotes get rid of the wire, but can loose signal depending on where you stand and are usually an upgrade option. There is one other option with electric jacks, quick-release or not. Non quick-release jacks lower and rise slowly at the rate the motor turns. Quick-release jack are convenient when you want to put the jack down. When the jacks are fully retracted on the truck, they are usually about 24 to 30 inches off the ground and with quick release jacks; you flip a lever and push the jack foot to the ground in seconds. It’s a handy option worth the nominal extra cost. There is also a camper stand system available that has the 4 corner jacks connected at the base by a big metal “ring”. This offers more stability for an unloaded camper, but it is an expensive aftermarket system that is not as widely used as standard electric jacks.

Camper struts are often considered as an option. These are the struts that connect the cab-over bed to a point on the truck between the hood and windshield. Only one camper manufacturer I’m aware of offers struts for the cab-over (Lance) these days. Most other manufactures do not offer the option and none of the manufactures (including Lance) require them anymore. Building techniques and materials have improved to the point that they are now rarities.

The hold down system is the last real camper unique option (the option is what type; all campers require something to hold them down). Strictly frame mounted hold-downs are bolted to the frame and have arms that stick out to connect to the camper beyond the truck body (the most common brand is Torque Lift). These systems have a direct connection to the truck, but are usually the most expensive option. Other systems are connected to the truck bed and/or the bumper, which is connected to the truck frame (the most common brand is Happyjack). These systems are usually cheaper, but they can cause damage to the body and bumper and cannot be removed without leaving evidence at a truck resale. Another system uses what is referred to as a belly bar. The truck has a bar mounted in the bed at the cab and the camper has a catch mounted under the pass through window that engages the bar when the camper is slid in. This has one less pair of chains to install, but is used much less. One reason is because the front bar has no opportunity for spring as noted next.

The hold down system should have springs on the chains or in the turnbuckle system. The springs are there for an important reason. If you install chains only and tighten them down fully, you run the risk of breaking something when you hit a hard bump. The springs allow the camper to move during a bump and the springs will pull the camper back into place. They allow a constant hold down force while reducing the chance of breaking something when you hit a shocking bump.

 

Truck Campers- A Word About Brakes
Another factor to consider is that ¾ ton and more trucks were built to tow. If you look at the owner's manual, there is usually a statement to the gist of "supplemental trailer brakes are required for trailers that weight over XXX lbs". That weight takes a loaded truck into consideration and is usually going to be much greater than any camper you put on the truck ends up being greater than the cargo capacity. The understanding I get from this is that the brakes have been designed to stop the loaded truck plus the figure the manufacturer has stated. Granted, a trailer load is different on the truck and perhaps the engineers have taken the resistance of the trailer's tires into consideration, but if a camper adds 4000 lbs on your truck and the manual says you don't need supplemental trailer brakes for trailers under 2000 lbs, then the worry is less (not erased) because the cargo capacity of the truck was 2600 lbs, plus 2000 lbs capacity of the no-brakes on a trailer = 4600 lbs of stopping power. This is not a license to overload. Just an observation of again why the 80% overloaded do it for so many miles.

Regardless of what your situation is, your camper will cause you to have to drive much more carefully. Braking will require more skill and braking at curves will instantly be radically different. Take it slow at first and develop a feel for your rig, and never become over-confident.

 

 

Truck Campers- Towing With A Truck Camper
Many people buy a truck camper to have the flexibility to tow utility, boat or horse trailers. The basic understanding of truck campers is that everything is about weight. Towing is no different. The hitch weight of your trailer must be taken into consideration for your cargo capacity. If you have a 4000 lb camper on a 6200 lb truck rated for 8800 total lbs, towing anything with a large hitch weight like a pontoon boat or car cargo trailer is not advised. Also, you have now opened up a new consideration, the Gross Combined Vehicle Weight Ratio (GCVWR). There are a lot of references to how heavy a trailer can be for most makes and models of trucks. If you're only carrying a trailer, this is very helpful info. If you're using a camper and trailer, especially heavily loaded trailers like horse trailers, you must know the GCVWR and stay with it much more strictly than the GVWR.

Why? A truck rated with a GVWR of 8,800 lbs will have a GCVWR of around 18,000 lbs, implying you can carry a 9,200 lb trailer. The engine, transmission, and differential are built to pull a total of 18,000 lbs. That’s why a truck which is 1,000 lbs over its 8,800 lb GVWR is not going to have engine and transmission troubles. As noted above, suspension and braking are the key considerations. But if you are going to add a trailer, it now becomes all about GCVWR and it’s not just the suspension, but everything about the truck that will be handling the load. If you have a 4000 lb camper, your trailer cannot be 9,200 lbs. This will be unsafe no matter what. A 4000 lb camper on a 6200 lb truck rated with a GCVWR of 18,000 lbs can only have a 7,800 lb trailer at the most. I won’t advocate anything else because going over is doubling and probably logarithmically increasing the hazards of overloading when compared to simply going over the vehicle gross weight only.

 

 

Truck Campers- Center of Gravity (COG)
The unique thing about a truck camper is that it sits in the back of a standard pickup as all cargo. Today’s typical truck campers typically weigh 3500 to 4000 lbs loaded for a weekend of fun. That’s a lot sitting back there. It’s a wonder your truck doesn’t flop over backwards with all of that weight (like that popular internet photo of a overloaded donkey cart lifting the donkey off the ground). What keeps this from happening? All makes of modern campers will list their Center of Gravity (COG). That number tells you the balance point of that camper. Ideally, the COG should be in front of the rear axel, in other words, that point should be between the center of the rear wheels and the cab of the truck. A minority of manufactures will measure their COG from the back of the camper towards the center, but most by far measure from the front of the camper (at the pass through window) back to the COG point.

First thing to do is go out to your truck and measure from the front of your truck bed (the wall behind the cab) to the center of the axle. Don’t trust that the center of your wheel well is the center of the axle. That distance will be your reference, usually 50 to 60 inches or more. Next check the camper manufacture’s listed COG. You want your camper’s COG to be 6” or shorter than the reference measurement you have for your truck, but no more than the distance you have measured.

Some people do drive around with the COG behind the axle (mostly not even knowing it). The weight of the cab and engine counterbalance, but this condition is inherently unsafe. To begin with, the rear axle is unduly overloaded. The front tires are also going to be lifted, loosing contact with the road. Steering and handling will be affected, and so on.

Also, you may have done the measurements and bought the proper camper and still end up with the COG behind the axle. That usually happens with improper loading. You will find this out when you go to the scales loaded. When you originally weighed the unloaded truck, the front axle was probably around 3500 lbs for a gas engine truck. If your loaded weight is less than 3500 lbs in front, you COG is off. You need to see if there is a way to reload the camper (take the bikes and chairs off of the ladder rack and install a front hitch and bike rack for example).

 

Now that all of that has been said, remember that some camper or truck manufacturers will figure their COG from the tailgate of the truck.  The above principals are the same, all that changes is keeping track of where to take your measurements from and how to then apply that to the camper.  

 

Text Box: Home PageAlso, Center of Gravity (COG) is referenced here and can more accurately be defined as the balance point from front to back of the camper, while a true (COG) may actually be located not just a certain distance measured along the bottom of the camper, but also up inside the camper.  This figure could be helpful to know, but only if you know how to relate it to your specific truck.  Most only know where the balance point is on their truck so COG has been generically used to refer to this dimension.