WDH and Sway Bars - Are They Needed?

I just wrapped up a 5400 mile trip. I used my WDH, but I did not install the sway bars. I did carry them with me, just in case. However, I wanted to see how the trailer performed without using the sway bars.

The trip was uneventful while traveling. There was very little sway if any and I can't say I noticed a difference without them versus with them.

I'm of the mind I can save +100lbs by using a standard hitch.

What's your opinion on the matter?

sway bars

The short answer YES!! When we had our 1990 25ft. Classic I followed behind DH in my car. It swayed causing many a motorist to pass us. Then our dealer let us know sway bars had become available for our brand of hitch. No more sway. Now we use sway bars on our 1996 26ft. Classic. If you got in an accident what would the insurance co. say?

I agree with sam - trailer sway is deadly and so easily preventable with the sway bars. You definitely DO NOT want to tow a trailer that heavy without a WDH, either. Not using one puts all the tongue weight on the rear axle of your tow vehicle which will almost certainly overload it, and, it lifts the front of your tow vehicle off the front axle which will have bad effects on your steering. Additionally, if you apply brakes without a WDH, the trailer will nose dive, lifting the front of your tow vehicle even more making the tow vehicle's rear brakes do all the work. Finally, the way a WDH is set up, it puts a downwards force on the hitch ball, which is forced upwards by the WDH bars. This makes the trailer stay hitched to the tow vehicle and prevents accidental separation.

Most State laws require a WDH if you tow a trailer of that size too. If you are in an accident and were not using one, you'd be in serious trouble.

- Jack

Hi all,

I've wondered about this with modern tow vehicles. I'm wondering if the OP had the weight-distribution bars in place and tight, so the weigh distribution is okay? But I've wondered whether the advent of modern 'anti-sway' tech on pickups and the like has made the sway bar itself redundant?

I'm not against redundant safety, but I've wondered at least. Thoughts welcome. My apologies if I'm totally missing the point here. Wouldn't be the first time!

r67northern said:

Hi all,

I've wondered about this with modern tow vehicles. I'm wondering if the OP had the weight-distribution bars in place and tight, so the weigh distribution is okay? But I've wondered whether the advent of modern 'anti-sway' tech on pickups and the like has made the sway bar itself redundant?

I'm not against redundant safety, but I've wondered at least. Thoughts welcome. My apologies if I'm totally missing the point here. Wouldn't be the first time!

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I THINK, and I may be wrong, that Shaihulud was asking if he could eliminate the WDH altogether (see his next to last sentence). And, bear in mind that a WDH can weigh close to 100# (mine weighs 70#).

Yes, since modern vehicles often offer sway control when towing, one probably doesn't need the added sway control on the WDH. However, my hitch has sway control built in to the hitch itself, and I cannot eliminate it without removing the weight distribution bars. And, a sway bar (if an add-on) doesn't add much to the hitch weight and certainly makes trailer sway much less likely. So, I'd say, keep it.

- Jack

Thanks for the responses Jack. To answer your first sentence in the last reply, yes I am asking if I can eliminate the WDH.

I did a little research based on your comment. Well, I used ChatGPT. It's reporting that no state requires WDHs. It went on to explain that some vehicle manuals may require it using the following example:

For instance, the 2018 Chevy Traverse owner's manual states that weight distribution and sway control are required when towing a trailer over 5,000 lbs.

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In the case of the 2206T, it came in at 3850lbs loaded, no water in the tanks. I believe with the tanks full it adds another 750lbs.

To your point about the increased tongue weight without the wdh. I cannot speak to this as I did not measure it. It's something I should and will do next time I have the trailer hitched.

I asked ChatGPT for the benefits of a WDH:

A WDH helps distribute the tongue weight of the trailer more evenly across the axles of the tow vehicle. This reduces the strain on the rear axle and helps balance the weight, preventing rear-end sag and improving stability.

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In my case I was running the trailer with a TPS. The tire pressures stated +/- 1.5 PSI front to rear with wider variations left and right due to uneven heating from the sun. It's certainly not a definitive measure of axle weight, but it is an indication of load distribution, IMO.

Sway, or fishtailing, is a common issue when towing. A WDH reduces sway by maintaining a more even load distribution, making it less likely for crosswinds, passing vehicles, or sudden steering changes to destabilize the trailer.
This even distribution enhances steering control and braking, especially during turns or emergency stops.

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I can't argue with this. The WDH does provide more stability depending on situations. I did have one close call during the trip where I had to brake hard to due to a semi locking up his brakes to stop in traffic with no working trailer lights. In that case the trailer stayed in line with the truck with no noticeable sway or loss of control.

By leveling the load, a WDH reduces strain on the rear suspension of the towing vehicle, decreasing the chances of premature wear and tear on suspension components.

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Something else I can't argue and which you stated as well.

A WDH provides a smoother, more comfortable ride by preventing the “see-saw” effect where the front end of the tow vehicle is raised, and the rear end sags. This balance minimizes jostling and bouncing, resulting in a more stable, comfortable towing experience.

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I can't say I noticed a difference. I'm considering adding airbags.

With a WDH, the tow vehicle sits more level, preventing the front from lifting. This improves driver visibility and ensures that headlights are correctly aimed, enhancing nighttime driving safety.

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The rear did sag more without the WDH.

A more balanced load can reduce drag by keeping the vehicle and trailer level, which may improve fuel economy compared to a non-WDH setup.

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If this is true, it's marginal. 13.9 MPG is the best I've gotten out of it. I noticed slightly higher MPG at higher altitudes. When I left Texas my MPG dropped from 14 MPG to 13.9 MPG.

I also looked up the disadvantages of a WDH, but they're not worth mentioning as the benefits outweigh the disadvantages.

The next long trip I take, I'll use it. But for short weekend trips, I think I'll leave it at home.

Air bags will level your tow vehicle and will also lift the front of your trailer too, but they DO NOT do anything about the tongue weight, which is ALL on your tow vehicle's rear axle. In my opinion, air bags should only be used when hauling very heavy loads in the bad of your truck, to level it and improve handling.

Trailer sway does not happen only when braking. It can happen when you hit a certain speed or when passing something big like a semi.

AND, I think ChatGPT may be wrong about no State requiring a WDH based on trailer size. In any case, a standard hitch will limit your tongue weight to no more than 500#I think. You can check your tow vehicle's towing requirements to verify this. I know my little 17ft HiLo has a tongue weight that is VERY close to 500# (I've measured it with a tongue weight scale), so I think your trailer will be heavier there. A WDH allows a higher tongue weight. Do you really want to take a chance on the stress a standard hitch will put on your tow vehicle, and the possible dangers of separation if something breaks?

Finally, your trailer has tandem axles. As such, it needs to ride level to even out the weight on each axle. If the front of the trailer is low, the front axle is carrying more weight than the rear. If the front is high, the opposite is true. A WDH will also let you level the trailer while towing, in addition to leveling your tow vehicle.

I honestly don't see why you would not take advantage of the benefits of a WDH, since you already have one.

- Jack

Boy, I sure do miss our HiLo…we always used our WDH and sway bars in the name of safety! Our 31ft was very easy to tow however being passed on the interstate one could feel the pull from the vehicle. We only had one incident where a car in front of us lost his wheel going at a nice speed-cars went everywhere trying to avoid being in an accident. Heavy traffic ended up stopped in an instant and road looked like a crowded parking lot! Our braking system-hitch set up worked flawlessly! We always used the WDH as it was necessary for the weight of the trailer. Our girl was perfectly level too.

If going to the storage facility around the corner the sway bar wasn’t necessary at 35 mph, but it definitely is needed on the highway!

Hope this helps! Enjoy!!

Weight distributing hitch.

Totally agree with Jack. He is a retired engineer and has a beautiful way with words. Very generous with answering posts.

I'm going to back off on my statement that State laws might require WDHs. I can't find anything to support that, so I concede that Shaihulud is right on that fact.

However, I'm seeing a consistent recommendation in towing publications for using a WDH if the towed weight (the trailer) is equal to or greater than 1/2 the tow vehicle weight.

Under this criteria, with my truck''s weight (6180# on a scale) and my trailer's weight (3500# on a scale), I NEED a WDH!

I think a 22ft HiLo may easily exceed 4000# if it is weighed on a scale, regardless of what the trailer brochure says the weight is. So, unless the tow vehicle is over 8000#, a WDH would be needed. I think a 22Ft trailer will also exceed the 500# tongue weight limit for a standard hitch.

And, if the trailer - tow vehicle combination was ever in an accident without a WDH, I'd expect both insurance companies and law enforcement to take a somewhat jaundiced eye toward the operator.

Again, I don't see what you gain by not using a WDH, but I certainly see a lot of potential losses. Trailer towing already adds an additional hazard to travels, shouldn't you try to minimize some of the bad effects?

- Jack

Things can go wrong so quickly and unexpectedly, I would say take any any advantage you can get.

When I towed with the Tundra, it had built in sway control, but my extra damper bar was used on my hitch too. Along with the distribution bars. On the 99 3/4 ton suburban I tow with now, same setup. It also tows better but that’s another thread.