When do you need a WDH

I used my 2720 all last summer without a WDH. After reading about them here and elswhere, I still can't figure out when you should have one. I have Super Springs on my truck, but that just keeps the rear from dropping when the trailer is hitched, as a mater of fact it hardly drops at all. But does not sagging in the rear mean sufficient weight is on the front tires? I just assumed a 1/2 ton pickup would tow the 2720 without any mods. Am I correct? I tow with a 2005 Nissan Titan.

You're going to get many responses to this post from some members who've become quite expert at the analysis (including the math) about the decision of when a WDH is appropriate.

We have one for our 3326K and our 1997 Suburban 1500 4WD because the tongue and trailer weights are near the Suburban factory recommended limits and because when the trailer is attached without it there is an obvious sag at the back of the TV and an obvious rise in the front. With the WDH the rig is level and tows well.

If you used your rig for a season and never missed having a WDH, that seems like pretty good indication that you don't need one! A full sized pickup like a Titan should do just fine. I tow with a 4wd Ford F150 SuperCrew and never feel the need for a WDH. Interestingly, I have a friend who dosen't use his WDH when towing a 2720 with his Ford Sport Trac but does when towing with his wife's Honda Odessy. - camp2canoe

I can tell you that I was advised by the TM factory to not use a WD hitch with my 1500HD towing a TM 2720. My rear bumper drops about 5/8 inch when towing and the front bumper raises about 1/2 inch.

Therefore, when towing a TM 2720, one might conclude that any truck bigger than mine quite likely does not need a WD hitch. However, no conclusion can be reached about trucks smaller than mine.

Wayne and I tend to both respond to theses WDH posts on the opposite end of the spectrum……which is a good thing, so that people can see different ideas on this and form their own opinion with their situation.

Since the new Titans and Tundras are now just as big as the big 3, ½ ton pickups and SUVs, I am going to give some stats on my F150 (all weights in pounds):

The Gross Axle Weight Ratings (listed on the driver’s door) is 3850 (rear) & 3750 (front).

Empty axle weights are 2560 (rear) & 3320 (front).

The truck axles go to 3260 (rear) & 3100 (front) when I add 480 to the hitch (425 TM tongue + 55 WDH equipment). So the rear truck axle goes up by 700 by just adding 480 to the hitch.

So, I still have close to 600 to go before I reach my GAWR. But when I load up scuba gear and tanks, firewood, toolboxes, extra water, etc., a canoe and bikes on the trac racks, plus the extra battery that I added to the tongue (after I did the weight-ins), plus water in the TM, I betcha I am real close to that GAWR.

There are several other variables with this. The front wheels take some of the load that is in the back of the truck, and the TM axle takes some of the load of the extra battery and water tank, so all (but probably most) of those loads is not on the rear axle. Also, if I didn’t have that extra 65 lbs. of WDH sticking farther out than a standard hitch, then that would also reduce the rear axle load.

2 other thing to consider: From what I have seen on shortbed trucks, the rear wheels sit about center of the bed on quad cab models, and sits forward of center of the bed in crew cab models. So if you have a crew cab style, if you load the bed up evenly throughout, you are putting even more weight on the back axle and taking it off the front. And with the heavier weight on the back axle without the WDH, I would think the chances of the "tail wagging the dog" would be less, since you now have more traction there....did that make sense??

If the WDH didn’t come with my TM, I might have never gone out and bought a setup. But now that I see the difference in weights, and handling, I go to the trouble of using it all of the time. I set the WDH up so that most of the weight is still on my rear axle, but I put a lot of that hitch weight back on the front and TM axle. And yes, I also did a bunch of weigh-ins with different setups.

The ½ ton pickup and SUVs are probably all capable of handling the TM without a WDH, as long as you don’t exceed the hitch, tire, and axle weight ratings. But everyone needs to do the math on their own vehicle, and decide what is best for their situation.

Chap

On the specific topic of the tongue weight causing unweighting of the TV front axle, I have no doubt that it is true.

However, it seems to me that even if my front axle is a little unweighted, it is still quite likely heavier than average, because I have 4wd.

Somewhere I have the weight for all three axles, but they aren't very handy. But I do know that all three axles wee within 100 pounds of each other. The weight that I cry is spread very evenly across all three axles. If I were to add a WD hitch I would disturb this even distribution. That does not seem to make a lot of sense to me. The purpose of the WD hitch is to rebalance the weight distribution. If you weight is badly distributed, then a WD hitch is a reasonable way to redistribute it.

Furthermore, the weight on my TM axle is 3380 and the limit is 3500. If I were to use a WD hitch and shift more than 120 pounds back to the TM axle, then I would be over the TM axle specification. For a few pounds I would not be concerned, but I certainly don't want to go much over the spec. Right now, I am just a little under.

In my particular situation, with a relatively long TV that is relatively heavy on the front axle, I am in decent shape as far a weight distribution goes.

I can not speak for other trucks, only my own particular configuration.

I found one of my old posts with my weights in it.

In:
http://www.trailmanorowners.com/foru...ht=3380&page=3

my weight was:

front axle 3500
rear axle 3860
TM axle 3380
total 10740

I am comfortable with this distribution.

One of these days I should look up the axle rating for my 2002 1500HD to see how close to those limits I am. Does anyone have a quick reference?

[Bill]

Can I add a "moderating" influence here?

Chap, you posted

Empty axle weights are 2560 (rear) & 3320 (front). The truck axles go to 3260 (rear) & 3100 (front) when I add 480 to the hitch (425 TM tongue + 55 WDH equipment). So the rear truck axle goes up by 700 by just adding 480 to the hitch.

Quite right. The other point, though, is that the front axle weight REDUCED by 220 pounds. The front end of the tow vehicle, which does all of the steering and more than half of the braking, is unweighted. Is 220 pounds significant? It depends on your tow vehicle, of course. Two hundred pounds may mean nothing on Wayne's 3/4 ton long-bed pickup - but it may be quite significant on a Honda Odyssey (say it ain't true, Canoe!) No matter what tow vehicle you have, reducing the front end weight is not what the engineers envisioned, especially when the load is increased by the presence of the trailer.

And Wayne - I have to agree that yes, you probably don't need a WDH. But you have a big vehicle with an extra-long wheelbase. A heavier vehicle reduces the need for a WDH - think about an 18-wheeler vs a Honda Civic. And a longer vehicle also reduces front end unweighting. But your vehicle is not typical of the questions that arise in the Towing Rigs Forum, and unfortunately, some new owners tend to say "He has a Chevy pickup, and I have a Chevy pickup, and he doesn't need a WDH, so I won't buy a WDH". That's not a good conclusion - but nonetheless it is what happens. It might be well to moderate this theme, unless the question is asked by someone who has a rig similar to yours. No offense intended ...

Bill

Bill, after getting off of my soapbox, I realized that I was preaching about the weight on the rear axle, but didn't stress the point about the loss of weight on the front axle, which is probably more important. My main concern is that people realize the geometry involved of adding weight behind the rear axle, and how that multiplies the weight on the rear axle, and takes away weight on the front axle. That is the big advantage of 5th wheelers....the weight is just forward of the rear axle, putting most of the weight on the rear axle, but some on the front axle also, as the manufacturers designed their vehicles to best perform.

Wayne has a very good point about not putting too much weight on the TM axle. If you "tighten" up that WDH too much, you might actually put too much weight back on the TM axle, stressing the already controversial trailer tires, and the axle. Too much "tightening" would also mess up the geometry of the TV by redistributing too much weight to the front of the TV.

My suggestion to all that question the need for a WDH, or everyone pulling a trailer for that matter, is to visit your local rock quarry, truck stop, or any place that has a truck scale........ and get some weights. Take the TV 1st, get the front and rear axles seperately, and total TV (which ought to add up). Go back with your TM soon after (so your gas tank is about the same), and weigh your truck front axle, total truck without the TM wheels on the scale, and then with only the TM wheels on the scale. You get your actual front axle and trailer axle weights, and you can calculate the rear axle and tongue weigh from these readings. If you have a WDH, do the weigh-ins without the bars in place, then a couple of weigh-ins with different chain lengths used. If you really want detailed readings, get some weigh-ins while camping ready......I intend to do that sometime in the future also.

Take these readings, compare the gains or losses on each axle, compare against the Gross Axle Weight Rating (GAWR) on both the TV and TM, and compare against the Gross Vehicle Weight Rating (GVWR) of your TV. Also calculate in your camping ready total payloads (they can add up fast), including people, and placement. I took my readings and found a couple of settings of the WDH that looked good, and then roaded tested to see which felt better while driving. I now use 2 different chain lengths depending on whether the truck bed and TM water are full, or if I am going with a lighter load.

As you can see, I have weighed my combo unit, and feel comfortable with the setup. Wayne has weighed his setup, and is comfortable with his. That doesn't mean that 1 of us is right, and the other is wrong. It means that we have both assessed our situation and made decisions on that.

I will now get off of my 2nd soapbox on this thread.

Chap

OK, I am back again already, after promising to sign off.

I just looked at Wayne's link (listed above) to a different forum post on his setup. Wayne is doing with his load with what I am doing with the WDH. He has put a lot of the camping supplies on the back seat of his truck, which would put some weight back on the front axle. I betcha that generator is to the front of the bed also, again weighing down the front end some. He has figured out how to negate the need for the WDH by maximizing his load placement. Plus he has the HD package, which is essentially a 3/4 ton truck suspension.

Also, he has a 6.5 foot bed on a crew cab truck. I think most trucks reduce the bed length to 5.5 foot when the go to the crew cab vs. quad cab....that extra foot of interior is taken away from the front of the bed, still leaving the same wheel base.....I think, I think.

I am going to try signing off of here and get a life.

Chap