sway bars?

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brianlclayton

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Joined
Mar 28, 2005
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2
Do sway bars really help that much?  I have a ford f-150 supercrew 4x4 with the towing package and tow a 25 travel trailer.  It doesn't seem to sway at all when I come accross semi or log trucks.  Some people say that it is necessary with the f-150 but I don't really see what it is going to improve.  Any information would be helpful.  I have only towed the trailer home from the dealer so I haven't really got to use it yet.  I do have a torsion bar setup with this combination.
 

N Smock

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Mar 9, 2005
Posts
246
Location
Long Branch, NJ
Brian

To answer your question - YES -.

The use of sway bars/ equalizers perform the function of
a) helping distribute the tounge load between the fore and aft wheels rather than just the rear wheels.
b) tighten up the coupling between the trailer and the truck allowing the trailer to gain some stablization from the truck suspension. Remember that the side of the trailer is a huge sail.

I had a GMC 1/2 tower with factory air shocks for towing. When i was towing on the Trans Canada at the head end of the Bay of Fundy the cross winds were so strong that I had to stop and tighten up an extra link on the bars to help keep the truck in line. Normally there was little motion (redirection) from buses motorhomes etc. You must remember that 1/2 ton truck suspensions are not much more ridgid than an auto - bet you love the plush ride of that truck. When towing with the 1/2 ton even with the equalizer bar I could feel the truck squirm on the suspansion. I was towing a 29 foot 6000 lb and 900 lb tounge.


Nelson
 

Carl L

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Mar 14, 2005
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west Los Angeles
brianlclayton said:
Do sway bars really help that much?? I have a ford f-150 supercrew 4x4 with the towing package and tow a 25 travel trailer.? It doesn't seem to sway at all when I come accross semi or log trucks.? Some people say that it is necessary with the f-150 but I don't really see what it is going to improve.? Any information would be helpful.? I have only towed the trailer home from the dealer so I haven't really got to use it yet.? I do have a torsion bar setup with this combination.

To answer your question, OH HELL YES.? :)

Sway control is a safety issue.? You never, ever want to experience uncontrolled yawing (sway).? First of all lets consider what is involved with your trailer stability system.

  • Tongue weight:? A stable trailer is nose heavy.? This is measured by tongue weight which should be 11-15% of the trailers actual weight, never less.? ?This is why you don't want to hang a motorcycle on the back of your trailer.

    Equalization of weight on tow vehicle axles:? This is what your ball mount and those spring bars (your "torsion bars") do.? They take the tongue weight bearing on your truck's rear axle and distribute it to the front axle via trunnions or a ring-and-pintle system.? ?If all the weight were to bear only on the rear axle, its maximum weight rating could be exceeded and even if not it would set up an over-steer condition, especially during breaking.? Over-steer is definitely not your friend when you are dragging around a few tons of trailer.

    Yaw/sway control:? ?Even if the foregoing are all in good order, you are still liable to sudden yawing.? Your trailer has a lot of what side area.? ?Sailors call this windage.? ?Crosswinds are going to push on it.? ?High speed vehicles with a big cross section are going to hit it with a shock wave.? [BTW semis, most of which have shock wave controls are not the worst offenders.? ?Panel vans, buses and motorhome are.]? The shock absorbing systems of trailers tend to be rudimentary to non-existent and at speed your trailer can be floating a bit.? So you correct with your steering.? And correct again.? And again.? And yet again.? Pretty soon you are nervous and tired.? ?Worse yet an exact combination of crosswind, vehicle speed, and shock wave from some Mario Andretti in a panel van, catches you by surprise and bad things begin to? happen.? ? Sway control is there to oppose any yawing and spare you that learning experience.? ? There are a number of schemes such as friction bars, Reese's cams on the spring bars, and Hensley's link geometry.? Use one.
In short, sway control is like a life jacket in a boat.? You can go without one for a time, but when you want it, you really want it.? ?
 

edjunior

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Apr 12, 2005
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2,592
Location
Roman Forest, TX.
Okay, I have a question.  I had a Montero Sport that required the equalizer bars to pull my 26' Ultra-Lite trailer.  After one pull, I went out and got and F-250 Super Duty.  I have used the equalizer bars with the new truck, and all seems to be well, but I'm wondering if there are any long-term effects since this is a much heavier duty towing vehicle.

Thanks.
 

Fizzban

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Joined
Jul 31, 2006
Posts
60
Location
Memphis
For what it is worth, I used to pull a 28 ft bumper pull with ONE sway bar, and it did fine.  Then I purchased a 36' and the trailer was wagging my suburban.  I put another on it and it made all the difference.  YES...use sway bars at least one.  You WILL find yourself in a situation where you are glad it is there!

Fizzban
 

Carl L

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Joined
Mar 14, 2005
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Location
west Los Angeles
edjunior said:
Okay, I have a question.? I had a Montero Sport that required the equalizer bars to pull my 26' Ultra-Lite trailer.? After one pull, I went out and got and F-250 Super Duty.? I have used the equalizer bars with the new truck, and all seems to be well, but I'm wondering if there are any long-term effects since this is a much heavier duty towing vehicle.

Thanks.

The tensile strength requirement of the spring bars on a weight distributing hitch is determined by your trailers tongue weight as much as anything.  Same trailer, new truck the same WD rig.  I have used my same bars on a 1500 Burb, a E350 Econoline Van, and a Ford Bronco, a bobtailed F150.

 
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