sway problem when towing

[walleyehunter]

How does one fix your boat trailer fish-tailing when pulling behind truck? My trailer pulls fine till I get up to about 70mph and then it tends to fishtail if I hit a bump or something. Nothing real bad but enough to where it keeps you awake on the way to or from the lake. My boat is already positioned so the transon is on the end trailer rollers. I heard this may mean my boat is tongue light. Is this the case and how do I fix it? Anti-sway bars maybe? Any help is appreciated.

Thanks!

[Hawgeye]

I don't know what type of trailer you have but typically you adjust the tongue weight by doing one of a couple things. One easy way to check is to move weight in the front of the boat. Put all of your batteries and gas cans up front and see if this helps while trailering. If it makes a difference it is probably tongue light and should be adjusted. If it does not help, you may have an alignment problem.

Many trailers allow you to move the entire axle and wheel assembly on the frame of the trailer. If you are tongue light, move the axle back, if you are tongue heavy move it forward. Check before bolting back on by weighing the tongue.

Someone can clarify this for me but I think the tongue weight should be about 10% of the weight of the traileing rig. If your boat and trailer is 1500lbs, the tongue weight should be 150lbs. You can measure this with a bathroom scale.

[Smitty]

Ditto to Hawgeye's post. If you do find it's a tongue weight issue, don't move teh boat on the trailer. It sounds like your boat is already positioned correctly, so you would need to move the axle on the trailer. Some have just U-bolt type brackets and you can adjust in any increments necessary. I have seen some also that have multiple holes drilled, so you have to move the axle in specific increments.

Don't go overboard with this method. You would be surprised how much you can shift the weight by moving the axle an inch or 2. I also remember seeing that the 10% rule is a good starting point.

Good luck

[Andy K]

You may also want to try a drop hitch. If your tow vehicle sits kind of high, you are changing the balance of the trailer with a normal hitch. A drop hitch will make your trailer sit more level and behave a lot better going down the road.

Andy K/CO

[walleyehunter]

Drop hitch sounds like the easiest place to start. Is there a general height guideline as far as how high the ball on the hitch should be sitting above the ground. I thought I once heard 18 inches. Does that sound right?

Thanks!

[Andy K]

I would say, look at your trailer when it is off of your truck. Use your tounge jack to level the trailer, and then measure that distance from the ground. You should be able to find a drop hitch that comes close to what you are looking for. Good luck!

[walleyehunter]

Thanks Andy K!
I will try that and see if it helps!
Good fishing!

[Tiny_Guy]

I had this problem with my full size bronco. I added a wind defector above the back window, the defector will push some air down onto the trailer and stopped the bouncing around. With the Bronco and boat, with cover on it, its a big airplane wing and lifts the boat and the bouncing around starts....Maybe this is your problem also.

[BlackSilver]

Usually this is caused (as you heard) by a tongue-light trailer. If you can't move the boat further forward, perhaps you can move the axle back a few inches? Both of my last two trailers allowed for that (ShoreLander and EZLoader).

SET the hook!!!

Hans/MN

[tailgunner]

You mentioned that you have the problem at 70 mph...did you know that trailer tires are rated for 65mph, max? Just some thing to think about...

[GR8WTHUNTER]

Your trailer needs to be level. Grab the level from the garage. Find level ground first. Pull your rig onto it and check with the level. Be sure to have the boat and truck loaded as if you were heading to the lake so you are setting up for actual load. I like to keep excess weight out of the boat and in the back of the truck. Check your tongue weight as mentioned above, should be 10%.

The problem could be with your tow vehicle also. Alignment, tire pressure, or even a "bad" tire or rim may cause these problems(check trailer tires too). You didn't mention your tow vehicle so I don't know what you have. If your tow vehicle is overloaded, including tongue weight, this could be an issue but haven't seen this since my buddy stopped pulling with his 76 pinto. Good luck finding the solution, it will help your nerves while driving and increase safety.

[Mike M (Sask)]

Here is a link to Shorland'r trailer site. If you go to step #3 on this page it tells you how to adjust the tounge weight.

http://www.shorelandr.com/pages/o_measureguide.html

Good Fish'n
Mike M (Sask)

[GR8WTHUNTER]

Wow, that is something to think about. I recall from buying tires over the years that tires have a weight and speed rating. The weight rating is in plain english, so many lbs at so many psi. The speed rating is a letter. I'm not sure where to find this or what each stands for anylonger. Does anybody know the facts?

[Tailgunner]

ALL trailer tires are speed rated for 65mph max, regardless of size.

[REW]

1. Before you do any thing - get your tongue weight to 10% of your loaded boat trailer weight.

2. Use a bathroom scale, or a pair of bathroom scales - divided by two with a two X 4 between the two scales, with your tongue gack on the 2X4 or 2X6 - if you have more tongue weight than one scale can weigh.

3. Then, do what ever is required to get the tongue weight to 10% of the boat weight.

If you are unsure as to your loaded rig weight - take it to one of the free way truck scales and get it weighed. They will all weigh the rig, if you ask them. Many folks very much underestimate the weight of their rig.

4. Then, many folks very much underestimate the amount of weigh that they should have on the tongue of their trailer.

For example - if you have a 3000 lb trailer, you should have 300 lbs on the hitch ball, from your rig.

5. If your boat is as far forward as you can move it - and if the weight is right for your on the water ride - your only option is to move the axle on your trailer.

Take care and enjoy.

REW