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Post by 71greengo on May 10, 2008 20:12:08 GMT -5
I built a 7' utility trailer to haul dirt/garbage/parts......I used it this weekend for the first load....empty it pulled straight and no swaying.........I loaded it with about a yard of topsoil and at 80 km an hour (50ish mph) it started swaying really bad, had to ease footoff gas and slowly slow down..........What causes trailer to sway?.......my design is as such... 7' long x 5' wide 2000lb leaf springs 14" wheels at proper air pressure.... I have short tongue at 42"...Should it be longer?, I know the longer the easier to back up... I offset the wheels forward of center line by 6" to keep tongue weight off my car...most trailers have wheels towards back of centerline ....when I loaded trailer I made sure load put plenty of weight on tongue.... should i move wheels closer to rear of trailer and should the tounge be longer.... I was pulling it with a 4 wheel drive Ford Escape any advise would be greatly appreciated, thanks!
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Post by uud looz on May 10, 2008 21:12:20 GMT -5
When there is too much weight behind the trailers axle causing the tongue weight to be less than 10% of the trailer's weight it has a natural tendency to sway. As I'm sure you know there are numerous other things that can contribute to sway such as tire underinflation; improper loading, overloading, or poor weight distribution; towing speeds; decending inclines; crosswinds; ect. I'm no expert, just my
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Post by Jer on May 10, 2008 21:19:32 GMT -5
Your concern about tongue weight is right on, since most sway situations are caused by excessive axle weight and not enough weight on the ball hitch.
Since you've already handicapped yourself by placing the axle forward 6 inches, you're just going to have to load that much more weight to the front.
I don't think you need to change the tongue length at this point...again, that's something that you can compensate for by distributing your load more to the front.
Without knowing how much a yard of topsoil weighs, I can't tell you if you were overloaded....but I will mention that when you say "proper air pressure" on the 14" tires, you need to remember that proper for an empty trailer and proper for a loaded one are entirely different.
When I have a load on any trailer I'm pulling, I always inflate the tires to maximum pressure...sometimes max plus 5%...underinflated tires act like big, mushy, rebound springs when the trailer they're under is loaded...they start a bouncing action that manifests itself physically into an ever increasing sway...not fun!!
You're just going to have to experiment with your particular trailer, a good rule of thumb for starters (on a trailer with a properly positioned axle to begin with) is about 60% of the load weight forward of the axle...yours is probably going to need about that if not a little less (due to the decreased volume available forward of the axle).
Also, check the load range on the tires (B, C, D, E, ST)....you might be underrated on those, which would cause sidewall flexing, which would also add to a sway situation....again, you're going to need to know the weight of your cargo ADDED to the Tare weight (Net) of your empty trailer.
And when you say "4 wheel drive" that makes me wonder if your hitch off of the Escape is at the right level...the trailer should sit as level as possible with the trailer hooked up...if the tongue is on an uphill slant then your weight is going to be more to the rear of the trailer...make sure you have a drop-hitch (2, 4, 6 inch) that is adequate to have your trailer level as it is being pulled.
That's all of the ideas I have at the moment...ain't nothing like trailer sway!!...My worst was pulling a set of double tanker trailers with more weight in the rear trailer than the front one, and no baffles (to prevent slosh) in either of them!!
Fun!
Jer.
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brock
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Post by brock on May 11, 2008 10:18:56 GMT -5
I tried to haul 27' I Beams on my 18' car hauler & didn't have any short I beams or extra load to add to the front of the trailer. My tongue weight didn't look horrible when I checked. I started out for home cautiously. I had to slow down a couple of times due to swaying, but nothing too bad. Speed limits increased & so did my confidence. As I started coming down a hill the swaying returned. I'm steering back & forth while trying to get slowed down. Long story short: I parked my truck on the trailer in the middle of the road.
The only thing I have learned that might have prevented this was to speed up. The trailer was both lifting the rear of the truck & pushing it.
Any other tips?
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DynoDave
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Post by DynoDave on May 11, 2008 11:32:28 GMT -5
I'm with the guys above, greengo. Tongue weight is the key here IMO.
If you have a utility trailer dealer near you, you ought to stop and measure the axle location on one of their trailers. You may have to move yours back.
Load distribution certainly plays a key. Next time you see the trailer, try to keep more weight forward of the axle, and see if that helps.
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Doright
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Post by Doright on May 13, 2008 11:52:35 GMT -5
Ditto what has already been said
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