# Why does my trailer fishtail?



## Silvercreek Farmer (Oct 13, 2005)

I pressed my 5x8 utility trailer into service for the first time last night and found that it fishtailed on me almost the entire trip. The only thing I can think of is that I was hauling 12 foot boards and the best I could do was slide them almost dead center with 2ft hanging off both ends, this balanced the trailer on the axel, however, I would have preferred to get more of the weight forward, maybe 60/40. My load was within specs, maybe 1000 lbs or so, and the tires were inflated properly. Any suggestions, was is just the weight distribution, or is there something else I should be looking for?


----------



## MELOC (Sep 26, 2005)

mechanical stuff like bad wheel bearings on one side or an axle that is out of alignment.


----------



## Batt (Sep 8, 2006)

You need at least 60-65# of weight on the trailer ball.


----------



## Oggie (May 29, 2003)

I sometimes pull a too-heavy trailer with a short-wheelbase truck. The load balance then seems to be even more critical.

The advantage to fishtailing at highway speeds is that it gets my heart rate up there where my doctor says it should be for cardiovascular exercise.


----------



## Ole Man Legrand (Nov 15, 2003)

The only thing I can think of is the toe end on the wheels. The front of the tires should be 1/8 inch more narrow from center of tire to center of other tire than the rear In other words the rear of the tires should be 1/8 wider than the front. Also check for a bent axle. Jay


----------



## Guest (Feb 12, 2008)

I have a small trailer that does that on me too. When I hook it up to my jeep it will fish tail. When I hook it up to my utility van it pulls great. The only thing I can figure out is the position of the trailer tongue. On my jeep the tongue is up high and does the fish tailing thing. On my van the tongue is down low and it doesn't fish tail then. 

So take a look at it when it's hooked up to your vehicle and see if the tongue is too high.


----------



## ace admirer (Oct 5, 2005)

like one other has already said, depending on trailer and axle number 10 to 20% of gross weight of a trailer has to be on the tongue. 200 min, lbs on a two axle trailer.. everyone wants a "balanced" tongue so its easy to move....that spells trouble. as others have said, tongue needs to be level. a raised tongue pushes up on the rear axle when brakes are applied, combine both problems and you can roll a high suv. consider yourself lucky...you made it home.


----------



## Batt (Sep 8, 2006)

r.h. in okla. said:


> I have a small trailer that does that on me too. When I hook it up to my jeep it will fish tail. When I hook it up to my utility van it pulls great. The only thing I can figure out is the position of the trailer tongue. On my jeep the tongue is up high and does the fish tailing thing. On my van the tongue is down low and it doesn't fish tail then.
> 
> So take a look at it when it's hooked up to your vehicle and see if the tongue is too high.


When the trailer ball is too high, it throws the weight back off the trailer ball and moves it back to the wheels. Measure the weight on the tongue at the height of the ball.


----------



## Cabin Fever (May 10, 2002)

ace admirer said:


> like one other has already said, depending on trailer and axle number 10 to 20% of gross weight of a trailer has to be on the tongue.....


BINGO! We have a winner!


----------



## Silvercreek Farmer (Oct 13, 2005)

Yeah, I thought the ball looked a little high, I put the hitch on, but the shop put the ball on the draw bar, they set it up as a 2" rise, I will have it swiched to a 2" drop and see if that helps. Unfortunatly I do not have wrenches big enough to take the ball off... 

Sounds like I may need to add some balast as well!


----------



## Oggie (May 29, 2003)

If you don't have the wrench to take the ball off, you don't have the wrench to keep the ball tight.

Buy a wrench (a cheap one will work for this limited duty).


----------



## fantasymaker (Aug 28, 2005)

It sounds as if you didnt load it properly. with10 to 20 percent of the weight on the hitch. Something else that is inportant is to get the center of mass of the load in front of the wheels as far as you can. its sorta the same thing but be aware that a lot of weight far behind the wheels has a bad effect even when its ballanced by weight in front of them.
Sometimes you run into a load like yours thats too long to get the weight forward on the hitch like you want. The way to deal with that is to load something heavy as far forward as you can bags of sand or fill containers with anything heavy(water, dirt etc) even secureing the spare tires to the tounge helps. Also pulling it with the heavyest vehical you can helps.
That might be a part of RH's problem but like Rh says the Geometry of the situation could have effect , When your trailer is loaded it should be level , so adjust the ball on the pulling vehical to be at the right height. the loaded behavior is the more critacal so if you cant adjust it for all situations favor the loaded height.


----------



## Michael Kawalek (Jun 21, 2007)

HI Matthew
Yes, stick with the suggestions above. The single most important factor is that about 7% (US Coast Guard recomendation) of the total weight of the trailer should be on the ball. If your combined total trailer weight is 1000lbs, then the weight on the tongue should be about 70lbs. You'll get the best performance if your ball is positioned so that the trailer frame is level. I hope that flipping the tongue over to drop the ball 4 inches is enough. Finally, are you using crossed safety chains? Never, never, never tow a trailer if you don't have safety chains bypassing the hitch. Once I saw this happen right in front of me. The hitch on a gardener's trailer failed, disconnected, and plowed right into the car to his left. Luckily for me I was able to pull off to the side of the road while the trailer when on its merry way.
Michael


----------



## Silvercreek Farmer (Oct 13, 2005)

Michael Kawalek said:


> Finally, are you using crossed safety chains?



YES!


----------



## GREENCOUNTYPETE (Jul 25, 2006)

well it's nearly unanimose bad loading not level negitive tong weight


----------



## Silvercreek Farmer (Oct 13, 2005)

Yeah, I think we have beat this horse...


----------



## fantasymaker (Aug 28, 2005)

Most of the weight on hitch recomendations here are the MINIMUM!
Think of the best pulling trilers there are ,semi trailers they have half the weight or more on the hitch,plus they are LONG longer tailers trail better and are easyer to back up. So handy ballast for both the puller and the trailer is a good idea just dont overload either.
Handy ballast.....plastic barrels that you can fill with water.


----------



## Guest (Feb 12, 2008)

r.h. in okla. said:


> I have a small trailer that does that on me too. When I hook it up to my jeep it will fish tail. When I hook it up to my utility van it pulls great. The only thing I can figure out is the position of the trailer tongue. On my jeep the tongue is up high and does the fish tailing thing. On my van the tongue is down low and it doesn't fish tail then.
> 
> So take a look at it when it's hooked up to your vehicle and see if the tongue is too high.


Bingo! The tongue has to have its share of the weight. In my case when I use my jeep most all the weight is shifted to the trailer axle making it fishtail, while my utility van the tongue and bumper is carrying its share of the load.


----------



## fantasymaker (Aug 28, 2005)

Matthew Lindsay said:


> Yeah, I think we have beat this horse...



Here feel free to use mine....:bdh:


----------



## texican (Oct 4, 2003)

I had to get one of the 'drop down' trailer hitches, otherwise all of my trailers would be dragging their rear ends in the pavement... you might need one of those, if your ball hitch is too high...


----------



## foxtrapper (Dec 23, 2003)

To the horror of many, I pull trailers with tongue weights all over the place. No problem in and of itself. All by itself, tongue weight has no effect on sway.

Trailer sway comes about from motion. Most folks can't figure that out for some reason. Lets start at the back and work forward.

1. If the trailer wiggles side to side over the tire contact patch, it's going to sway. This is typically caused by weak tire sidewalls, low tire pressure, loose wheel bearings, and sloppy trailer suspension.

2. Cheap trailers tend to have long flimsy tongues. You can get a lot of nice sway going with this, especially if you load them nose heavy. The longer and flimsier the tongue, the more the trailer sways as it turns from side to side.

3. A sloppy hitch lets the nose of the trailer turn side to side. It's not common with car trailers, but if you ever pull with a pintle hook, you'll certainly learn about it.

4. A poor hitch on the tow vehicle. Many of them are really poorly built, particularly the universal hitches and the lightweight category I-II hitches. They let the hitch ball move side to side, turning the trailer nose from side to side, so it sways back and forth going down the road.

5. The tow vehicle tires. Front and rear. Most tow vehicles have *lousy* towing tires. With the nice squishy sidewalls, the tow vehicle sways side to side, swinging the hitch ball side to side, turning the trailer nose from side to side, so it sways back and forth going down the road. I watch this one all the time. Foolishly, many people ignore the front tires of the tow vehicle. They come into play for stability almost every bit as much as the rears. 

6. Trailer loading. It's usually not a factor. But overall, centering the weight of the load over the axle will create the least leverage on the trailer, and keep the induction of sway to a minimum. I know, people swear about trailer loading. That's fine. What they are doing is masking the problem, not addressing it. Same with slowing down.

7. Trailer length. Short trailers are angularly affected by the nose far more than long trailers. As such, they are much more prone to wagging. And as such, they are much more demanding of good tires and such to prevent them from wagging.


----------



## wy_white_wolf (Oct 14, 2004)

8. Axle slightly out of alignment or bent. An axle out of alignment (dogtracking) will jerk to one side. Many people confuse it with swaying. Usually it not noticable empty and gets worse the more it's loaded. A bent axle that puts the two wheels out of alignment with eachother will sway or jerk (depends on how it is out of alignment) as it can't decide which tire to track.


----------



## fantasymaker (Aug 28, 2005)

8a worse yet both tires angled off to the same side.


----------



## Hooligan (Jul 18, 2007)

Tongue weight has much to do with trailer sway. 

I played with enough boat trailers to know that for a fact. The last boat I dragged home I drove a thousand miles to get. The owner had cut off part of the tongue and pushed the boat back on the trailer to fit it in his garage.

I could pick up the tongue with three fingers. The entire package weighed about 3000 lbs.

That particular set up would start swaying behind my F 150 at about 60 mph. At 70mph is was down right scary.

I re-rigged the trailer set up when I got home, getting it to have about 200 lbs on the tongue and it rides nice at 75 mph now.

You want your trailer set up so that there is enough weight on the tongue so the trailer has a nice "three point" stance. Not enough weight on the tongue and the tongue will want to go up and down and side to side at the will of the forces placed by the entire load on the axle.

This of course refers to tow vehicles with the hitch points aft of the axle.

Tractor trailers are completely different animals and are ruled by different rules of physics.


----------



## Silvercreek Farmer (Oct 13, 2005)

Dropped the ball 2" and found a hunk of steel for ballast, problem solved!


----------

