So I feel dumb asking these questions as I should probably know better. But here goes...
I have a 2012 FX4 Supercrew. I tow a 28' travel trailer that allegedly weighs about 5000 lbs dry. It came with a weight distribution hitch which I have always used. Last weekend the 4 hour drive was a little more white-knuckled than I would prefer. The trailer was giving me all kinds of sway issues and was unpredictable over 65 MPH. Once I got to my destination, I realized that I needed more tongue weight. The only other time this happened was when I had the bikes on the trailer's bumper mounted rack. I figured the easiest way to fix this was to move the bikes inside the trailer and to the front. I also left the freshwater tank partially full as it is in front of the trailer axles. I am really not a fan of either of these options, but I also didn't appreciate the stressful drive up north. On the way home, the system drove pretty well. I was able to motor along at 75 with little to no issues. Before I go on, I will point out that my goal is not speed, but to get a smoother and SAFER ride for the family.

I have begun putting more thought into weight distribution and possibly adding the Firestone airbags. But I wonder if what I am going to do will just keep taking more weight off the tongue. So I ask the following questions, which I imagine sound silly to those of you who tow a lot:

1) Is it possible to take TOO MUCH weight off the tongue with the weight distribution hitch? I initially figured that if using the 4th link on the chain, trying to get to the 5th or 6th link was better. But if I really crank down on the WDH, am I just sending that weight back off of the tongue to the back of the trailer? Or is it keeping the weight on the tongue but sending some of it to the front axle?

2) If I add the Firestone air bags am I just creating the same problem? In the future, I plan on loading the trailer more tongue heavy in order to reduce sway. As I add more weight, I would prefer to keep the ride of the truck smoother and level. So I was thinking of adding the Firestone f2525 ride right bags. But if I use these and level the back of the truck, is that going to reduce the tongue weight by sitting the trailer back?

3) Am I right to assume that I want the trailer AND the truck to sit as close to level as possible? I am hoping that by correctly using the WDH and/or the air bags, I can keep the whole rig level, but also add more hitch weight. Is this even possible, or am I really just adding hitch weight and then sending it back to the trailer by leveling things out?

Thanks for any insight!

 

a2pfunk, you ask good questions and they reveal much of what you know and don't know about trailer towing.

First, you are correct in thinking proper tongue weight will reduce the tendency of the trailer to sway. Ideally, it should be between 10-15% of the trailer's total weight when you are towing. That would make the tongue weight between 500-750# if your trailer is really 5000# in its traveling configuration. The only way to measure the tongue weight is to use a tongue weight scale (I have one from Sherline) or, weigh the entire trailer on a CAT scale separated from your tow vehicle and then connect it to the hitch (without applying the weight distributing bars) and weighing just the trailer axle(s) on the rear scale. The difference would be your tongue weight. You can also weigh the truck's axles both times on the front scales and you would see that tongue weight increasing the load mostly on the rear axle.

Now, a WDH DOES NOT reduce the tongue weight at all. It simply "lifts" the tongue/hitch connection, taking some of the increased load off the rear axle of the tow vehicle and transferring it to the front axle. It also adds more load to the trailer axle(s) in doing this, of course. Your goal is to try to make the increased load on both tow vehicle axles to be nearly equal, so that the truck does not sit nose up or nose down.

Ideally, the trailer SHOULD also ride level if it is sitting on level ground.

Adding a sway control device to your WDH might be a way to keep things under control if your tongue weight is in the good range and you still get sway. These are not expensive devices and they work well. Probably, for your hitch, such a device will look a bit like a shock absorber, and it works in a similar manner - to dampen the back and forth motion that is sway.

Air bags are NOT a good idea if you use a WDH. They will simply raise the frame of the truck off the rear axle, but all the weight is still there anyway. They can cause you to adjust your WDH improperly. If you increase your tongue weight by loading the trailer differently, simply attach the WDH chains at a shorter length to transfer some of that increased load to the front of the tow vehicle. Probably, there would be no more than one link difference between different trailer loadings.

Air bags would be good if you load a bunch of concrete in your truck bed, or tow a trailer without a WDH. They level your truck in those conditions, but the weight is still on the rear axle.

You should also adjust the hitch ball on your trailer so that it is maybe just slightly higher than the tongue ball receptacle if the trailer is sitting level behind the truck but not hooked up. This will make it easier to get the proper weight transfer with the WDH hooked up.

Hope I've helped. If anything's unclear, feel free to ask me to clarify. There are also many good u-tube videos that show you how to hook up a WDH - look for them.

- Jack

 

You can add a rear anti sway bar to the rear axle in the truck, will help with body roll.


If it is a flat feeling back and forth motion it's also possible you have too much tongue weight


If it feels like the front of the truck is lifting and floaty feeling, too much tongue
If it feels like the trailer is pushing the back of the truck side to side, too much tongue

If it feels like the rear axle of the truck isn't compliant and feels light it's not enough tongue weight

 

Those comments by Patman illustrate why it's a good idea to find out what your actual tongue weight is. A good rule of thumb is to shoot for 12% of the trailer total weight.

- Jack

 

Thanks so much for the quick reply, it was very helpful!

I started off by lowering the ball on my truck so that it is only about 1" above the hitch when the truck and trailer are both parked level. Unfortunately, I didn't have time to take it for a spin on the highway, but the trailer is sitting a lot more level now.

I guess I am still confused about the WDH and airbags combo. You said that a WDH will put more load back on the trailer axles. Doesn't this mean that it has to be taking some of that load off the truck and therefore reducing the tongue weight? Also, what kind of problems can arise from combining the airbags and WDH? My goal is to distribute the load using the WDH and then level out the rear and improve the ride quality with the airbags (althoughmy limited research tells me I need to fill the bags first then adjust the wdh).

To be honest, the air bags might be out for me anyhow. I saw in another thread where somebody said it was a 5hr install. I don't know where I'd find that kind of time without The Wife nagging me to tackle her list!

Thanks again!
Patrick

 

Hi Patrick,

This might help you visualize how the WD hitch works in relation to the tongue weight.

Think of how a wheel barrow works.

It has a front wheel, the load area, the rear skids and the 2 handles.

Think of the front wheel as your trucks front axle. Think of the load as the tongue weight and the skids as the rear axle and the handles as the WD bars.

Plop a #80 bag of cement in it and it's weight is now distributed between the front wheel and the rear skids. (front and rear axles of your truck)

When you lift up on the handles, what happens with the load? The bag of cement still weighs #80. You've shifted weight to the front wheel and if you don't lift it up all the way, you have reduced weight from the rear skids.

You have also transferred weight thru the handles to your legs/feet (think of that as the trailer axles).

Nowhere in any of this does that bag of cement change weight.

Hope that helps!

Mitch

 

Hi Mitch,
Great analogy, thanks. Problem is, I understand the idea that weight isn't going anywhere and is just being redistributed. I guess I'm not phrasing my question properly. My problem last weekend was that I didn't have enough tongue weight. I am wondering if I am defeating myself when I load the trailer to be more tongue-heavy but then the wdh distributes that weight off of the tongue and back onto the rear axles. If this is the case then it seems that using the wdh would be part of my problem.

As I said, I lowered the ball a few inches to level the trailer. I'm hoping that helps distribute the weight more evenly.

 

No, you're still misunderstanding the way a WDH works. It does not take ANY weight off the trailer tongue. It DOES take the tongue's weight off the rear axle of the tow vehicle and distributes it to the front axle and to the trailer's axle(s).

All of the trailer tongue's weight is STILL on the ball of your trailer hitch.

- Jack

 

When you just plop the trailer on the hitch, you reduce your trucks front axle weight and increase the trucks rear axle weight.

When you apply the WD, it tries to move that added rear axle weight to the front, and since the bars attach to the trailers tongue, it also adds some to the trailer axle.

When you add more tongue weight, it just adds more to the rear axle than it did when it had the lighter tongue weight.

The actual tongue weight does not change. If it starts out at #750, it's still #750 after the WD is set. If you increase the tongue weight to say #850, it's still #850 after. The WD is just re-distributing that extra #100 between the 3 axles.

With the heavier tongue weight, that in itself, will help with how a trailer tows..

One time I went to the local Home store and got some cement bags. I took my little 8' utility trailer. I got lazy and just tossed about 4 bags behind the axle of the trailer.

On that mile drive home, that little trailer was all over the place and I was only going 30 mph!

When properly loaded, it'll tow straight as an arrow..

Good luck!

Mitch

 

Think I'm getting it now. Thanks guys!

 

What hitch are you using? Does it have sway control built in?

I just upgraded campers (a bit longer and heavier than yours) and got the Blue Ox WD hitch... the only highway driving I've done is to pull it home (about 1.5 hours), but it pulled great. Much better than my old WD hitch and sway bar with the old camper.


FYI - I've also installed air springs on my truck. They can be helpful if you need to level out the truck a bit, but don't go putting in 50-60 PSI just to make it work. I pulled the camper home (city driving 6 miles) last weekend with 20 PSI in the bags and it helped level it out.
Without the air springs, I am still well within the limits... but I installed longer mud flaps and they would drag when I hit bumps. Adding a bit more support levels it out and makes it ride a little better.


And you should probably reconsider your driving speed. Most (all?) trailer tires are rated at 60 MPH. Maybe you can push it to 65, but driving 75 MPH with your family and a 28' trailer that probably weighs 8-9000 pounds (or more when loaded) is a bad idea.

 

Thanks for all the help guys. I think I have a better understanding of some of the physics now. I ended up buying the Firestone air bags and installed them myself. It was so easy, I am sometimes worried I may have done it wrong!

They made a huge difference and I wish I had done it a few years back. I have a 28 foot TT and I am well within my weight limits. The WDH definitely helps, but the airbags greatly improved my ride.

 

If you don't have a sway control device on the trailer tongue, buy one NOW!
When I towed a 25' TT, I first pulled it 600 miles each way on vacation. I was using a Reese WDH and pulling it with a SWB F150. I was a road hazard the TT was swaying so much. I then installed the Reese dual cam sway control devices and it eliminated the sway. My WDH had 1,000 lb rated bars which was a little overkill for the trailer i had but that made the dual cam sway control work even better.

 

In the 4 years I have had this trailer, sway has not been an issue. I only ever put the friction sway unit on once. Even in a 4 hour drive with a 20 mile crosswind, it was not a problem. I feel a little tug when passing or being passed by semis but that is it... EXCEPT for the two times that I had loading issues with my trailer. The thing was all over. Once I figured that it was an issue of improper loading and that I needed more tongue weight the thing has towed great.

I just ordered a Fastway E2 WDH which has sway control integrated. Hopefully that does the trick with the new TT.

Thanks!