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Seattle_Lion's avatar
Seattle_Lion
Explorer
Jan 16, 2014

Lessons from a new TT owner

I think this might be a helpful guide for folks like me who are new to RV's and TT's. There is so much to know that dealers (RV and truck) just don't tell us. It turns out that the information is out there, but it took me quite a while to know I needed to find it. Maybe this would be a good sticky thread that could provide a starting point for people like me.

Size (and weight) Counts
We bought our truck a month or two before deciding to get a TT. So, we made the first mistake: not matching the TT to what we own. Of course we showed the RV salesman our truck so he could help us do this right. As it turns out, he didn't have a real clue.

A TT has four very important numbers you need to know:

Dry Weight - This is the weight of the TT delivered to you. Chances are that this is not the weight on the side of the TT. That weight probably doesn't include options and misc. stuff. Our trailer (Kodiak) was weighed at the factory and the actual shipped weight was on a sticker. Even this was incorrect since it didn't included propane tanks or batteries. However, the number you get is a good guide.

Maximum Payload - This is the most weight you can safely add to the trailer. Things like tire limits, axles and other stuff govern the payload. Sometimes you just get the MGVWR (Maximum Gross Vehicle Weight Rating), which is the most the trailer can weigh including everything. You can get your payload number by subtracting the dry weight from this.

Tongue Weight - This is the amount of the trailer's weight that is applied to your hitch. It is very important. Most manufacturers publish this as a percentage of the trailer's dry weight. For example, our trailer has a dry weight of 6000 lbs. Kodiak says the tongue weight is 13%. So, unloaded the tongue weight should be 13% of 6,000 or 780 lbs (more or less). If we add 1,000 lbs of stuff, the tongue weight is approximately 13% of 7,000 lbs or 910 lbs. Bear in mind that any water in waste or fresh water tanks adds 8lbs for each and every gallon.

Maximum Gross Vehicle Weight Rating (MGVWR) - This is always on the metal plate on the front left of the trailer.

Your Tow Vehicle (TV)
Truck commercials generally brag about towing capacity for the advertised trucks. This number is actually one of the less important values you need to know. Here are the numbers you want:

Maximum Payload - This is the amount of weight the truck can carry. It includes you, your family, pets, gas, and other stuff in the truck, including the bed. There is generally a yellow sticker on the sill below the driver's door with a payload number. You can get an idea of this value from the various web pages provided by the manufacturer.

Maximum Gross Vehicle Weight Rating (MGVWR)- This is on the plate inside the driver's door. This is the most the truck can safely weigh. It is a very important number.

Those numbers are really easy to find. However, you need a bit more:

Maximum hitch/receiver weight with and without a weight distributing hitch (more on that later). This number is sometimes on the side of the hitch receiver itself. It can also be found by searching for it on the web for your specific vehicle. It is a surprisingly small number. My ford F350 diesel superduty truck has only an 850 lb hitch/receiver weight limit without a Weight Distributing Hitch (WDH) and a 1,250 lb. limit with one.

Matching the trailer and the truck

First the easiest number: Your truck must be rated to pull the fully loaded weight of your trailer. My truck can pull 14,000 lbs and my trailer weighs 7,000 lbs. No problem.

Next is the truck's payload. Before we bought the F350, we had a F150 and it has a payload capacity of 1,250 lbs (crew cab and lots of luxury stuff). We calculated the approximate tongue weight at 910 lbs. Ok, subtract 910 from the 1,250 payload capacity of the truck and you get 340 lbs. That number represents the weight of everyone and everything in the truck. Two people and their lunches probably puts you over the MGVWR of the truck. It doesn't mean you can't tow the TT with that truck, but you are doing it at your own risk.

Another number: Receiver / Hitch max weight. Ok, I don't know that number for my old truck, but the F350 has a 850 lb limit without a weight distributing hitch and a 1,250 limit with one. Since my tongue weight is 910 lbs, clearly you can't safely tow that trailer without that kind of hitch.

What is a weight distributing hitch (WDH)
This is a special kind of hitch that transfers some of the tongue weight to the front wheels of the truck. This brings us to that max hitch / receiver number. The reason it is there and it counts is because when you put weight on the rear wheels of the truck, it tends to push the back down and the front up. This takes weight off the front tires and can reduce your ability to steer and stop. The WDH helps with that. Check your owners manual for setup instructions. While some very experienced RV'ers happily tow without one, a WDH is one of the best things you can buy for your new TT.

Weigh your rig
All of the truck and trailer numbers above are approximations based on reading and guess work. Nothing substitutes for actually weighing your rig. There are several threads on how to do this. It isn't all that complicated, but it can certainly be eye opening. Find a scale and do it as soon as you can.
Weighing your rig

Now, the estimates are very important to help with purchase decisions. You shouldn't buy a trailer or truck without assuring yourself that they will work together. Lots of stuff on here about that too.

Trailer Sway
You will see a lot written about this issue. It is one of the most dangerous and scary things about towing a trailer. We experienced it a few times over last summer. A strong cross wind caused the trailer to move out of a straight line with the TV (towing vehicle). Trying to correct this with steering the truck can make it worse or better...it takes experience and skill. Also, when passing or being passed by a big tractor-trailer the change in pressure caused by this big rig can also pull or push your trailer off course. In my experience, I felt like I was being sucked closer to the big rig. I learned to compensate with my steering. I have been told that the reason for some of this sway was the mismatch between the F150 and my trailer, and that with the new, heavy duty truck it will be much less. Nothing can spoil a trip like driving white knuckles to and from the campground.

We started our adventure in June 2013 and had a great summer traveling around the Northwest. My only regret is that I didn't know what information I really needed to make the right decisions getting started. I hope this helps; and I hope others will contribute their considerable wisdom too. I still have so much to learn!
  • jmtandem wrote:


    Lastly, the cowboys of old knew that it was almost impossible to have too much horse. Maybe they knew something.


    Sorry but I don't believe any cowboy rode a draft horse.
    Maybe they really did know something.
  • What is a weight distributing hitch (WDH)
    This is a special kind of hitch that transfers some of the tongue weight to the front wheels of the truck. This brings us to that max hitch / receiver number. The reason it is there and it counts is because when you put weight on the rear wheels of the truck, it tends to push the back down and the front up. This takes weight off the front tires and can reduce your ability to steer and stop. The WDH helps with that. Check your owners manual for setup instructions. While some very experienced RV'ers happily tow without one, a WDH is one of the best things you can buy for your new TT.



    A weight distribution hitch properly adjusted and tensioned transfers about 20-25 percent of the redistributed weight back to the trailer axles and tires. This is important as so many trailers come with barely able axles and tires. Many trailers have axles that combined do not carry the weight of the trailer and instead rely on the tongue weight to carry about 13 percent of the trailers gross weight. Additonally, even with the axle equalizer between the springs between the axles, the axles do not carry the same weights, nor do the axles carry the same weights on either side. Typically the side with the slideout is heavier and if no slideout then the side with the refrigerator.

    Not all the redistributed weight from a well set up WDH transfers the redistributed weight to the front axle of the tow vehicle. Today, most of the prevailing logic is not to exceed the front axle weight that is present not towing. In other words, do not put more weight on the front axle than was there previously without the trailer. That means a trip to the scales to add back to the front axle using WDH only that amount of weight taken off the front axle due to the trailer. And measuring with a ruler from the bumper to the ground does not work well with some modern vehicles that have progressive springs or stop bumpers on the front axle travel. It takes a trip to the scales to dial in the WDH.

    As far as the sway issue, be sure you have at least 10 percent of the trailer's total weight on the ball. Less than 10 percent is an invitation to sway. The Hensley, ProPride and PullRite hitches control sway, most other hitches are simply friction based and mitigate sway. There is a difference.

    As previously mentioned when an RV salesman lips are moving, most of what is coming out is likely inaccurate or heavily biased to make a sale. Too bad.

    Lastly, the cowboys of old knew that it was almost impossible to have too much horse. Maybe they knew something.
  • # 1. Do not believe the salesman,they want your money.
    # 2. Do not believe the salesman.