trailer sway at 60

[BillP]

Re: trailer sway at 60

Don't adjust trailer to remove tongue weight. I think you mean don't adjust the trailer to get rid of the squat?

 

[DJ]

Re: trailer sway at 60

I meant do not move the boat on the trailer-if it fits well. If you need to adjust tongue weight, moving the axle is the best choice.

 

[BillP]

Re: trailer sway at 60

A friend of mine bought a new Float-On brand trailer and took his boat to them (factory) for tongue weight adjustment. I went with him, they moved the boat, not the axles. I've also moved the winch stand fwd and aft to change boat positions to do tongue weights and had no problems. The only time I'd move the axle is when the boat won't fit right and you have to move them.

 

[regjen]

Re: trailer sway at 60

I meant do not move the boat on the trailer-if it fits well. If you need to adjust tongue weight, moving the axle is the best choice.

My situation is similar to the original post. I have a V8 Explorer rated for 5k lbs. Boat weighs 3k lbs and I'm guessing 1200 for single axle trailer. Explorer pulls fine on the highway at 55mph (which I'm fine with) but every now and then I get some sway. My friend recommend we move the axle forward roughly a foot. Is that too drastic of move? I'm trying to get an idea of how much weight would should I expect to be added to the tongue by shifting the axle forward 6", 12" etc. Thanks.

 

[Nova II 260]

Re: trailer sway at 60

Moving the axle forward will give you less tongue weight. Depending on how much weight you need to fill your optimum tongue weight, you could try moving the winch post forward thereby adding tongue weight.

 

[regjen]

Re: trailer sway at 60

Now I'm confused (the physics part of my brain is not kickin in). If I move the axle forward (e.g. closer to the front of the trailer) that decreases the tongue weight?

So does the axle being moved back x - inches take less less weight off the back-end and redistribute?

Just want to be sure. Thanks.

 

[Nova II 260]

Re: trailer sway at 60

Think of a Lever & Fulcrum. In the pics move the fulcrum (your axle).
Tongue weight distribution

 

[jeeperman]

Re: trailer sway at 60

Your rig might not sway at all until you reach that magic highway speed.

Your boat is built to plane (rise) on water given enough speed.
When you get going fast enough on the highway, guess what, your boat is trying to plane on air, thus unloading the tongue resulting in sway as your boat tries to take the trailer in another direction.

 

[scrobo]

Re: trailer sway at 60

Your rig might not sway at all until you reach that magic highway speed.

Your boat is built to plane (rise) on water given enough speed.
When you get going fast enough on the highway, guess what, your boat is trying to plane on air, thus unloading the tongue resulting in sway as your boat tries to take the trailer in another direction.

I was wondering the same thing with my sway. I adjusted the tongue weight and switched to bias tires. I still got sway heading up north at about 65mph but if I slowed down or sped up a bit it would stop. My wife brought up the planing issue and I poo-pooed it off since air and water have different physical properties.

Would the boat really react to air pressure the same way it acts to the water? I figured with a much lower density and flow characteristics it would not have been the issue.

 

[Nova II 260]

Re: trailer sway at 60

I have gone 75mph (I don't normaly) with out any white knuckling. But I'm pretty heavy and have a dual axle trailer. I pull with a Chevy Express van so I'm sure my draft is negative air pressure directly behind it. With a pick-up, since its open, there is probably some turbulant air at the boat's bow. Enough to lift the boat and cause a deminishing of tongue weight...who knows.
ScroBo, if you are sittiing level ,I'd try moving your boat forward a little more.
perhaps you need 14% instead of 10% tongue weight, or what ever you got.
There is only proven rule's of thumb. Every rig/boat and trailer combo is going to react a little different. As with anything else, If not Happy, Change it.

 

[Have Fun Today]

Re: trailer sway at 60

In addition to all of the things already mentioned, check the literature that came with the receiver mounted under your rear bumper...it may even have a sticker on the hitch. The manufacturer probably recommends a weight-distributing hitch above a certain GTW. A weight-distributing hitch will take some of the tongue weight and transfer it from the rear wheels to the front wheels on your tow vehicle, making the towing much more stable. I did this with my Avalanche for my 6000 lb boat/trailer combination and have always had a very stable ride. When you start to approach the max towing weight of your vehicle, a weight distributing hitch is a good investment.

 

[sjlnys]

Re: trailer sway at 60

Usually trailer sway is a result of two little tonge weight. Recommended tounge weight for boats is 5 - 7% of the total towed weight. I was having the same problem with my 23' walkaround on a tandem axle aluminum bunk trailer, towing with a Ford Expedition. I went to a public scale, checked the total weight of the trailer and the tonge weight, adjusted the axles and boat position to obtain the correct weght (heavier tonge weight favoring the 7% based on the calculations). The problem went away and I can now accelerate to 70+MPH when passing without any trailer sway. I usually run at the speed limit (65) on the interstate with no problems at all. Also when you load the boat for traveling, you need to balance the item position in the boat so as not to throw off your tonge weight. I usually load a little more in the cabin which makes it a little bow heavy. I also added Air-Lift air bags in my rear springs and inflate them to the rcommended 35 lbs when trailering. Even if your tonge weight is correct, if your tow vehcle sags when you put the trailer on it, that will effect your steering and increase possibility of trailer sway. Trailer Boat Magazine and their web site has a lot of good information on setting up a trailer and tow vehicle. Good luck.

 

[regjen]

Re: trailer sway at 60

Nova II 260, lever and fulcrum analogy...Genius! Seriously though, it makes sense now and certainly something I can incrementally adjust for the best possible ride. Preciate everyone's input.

 

[superflydudebike]

Re: trailer sway at 60

Plus, stop listening to Sammy Haggar tunes while you drive.