Diagnosis, analysis, opinions needed to solve trailer sway

weldingisfun · Jul 8, 2012

More to chew on. Having read all of your input I was ready to shorten the trailer by 12 inches. I agree that moving the axle would be to much work and trouble.

One thing I failed to mention at the beginning was the floorboards had been removed from the trailer (Rear). I am thinking that added to the swaying, but here is what really contributed to the problem. Whoever built this thing was really into building for strength. The gate consisted of two parts; the first part is hinged to swing out (Gate). The gate is build from angle and flat stock all of it 5/16" thick. The gate, as seen in Pic 2, weighs at least 125 pounds. Inside the gate, he added a lift gate (Lift Gate) which I first thought was made from 3/4" OD round pipe. Wrong! It is 3/4" solid round stock. It has to weigh between 75 to 80 pounds.

Once I had removed the gates, I took the trailer back out on the road and it never even tried to sway, even at 65 mph.

I do intend to replace the car tires with trailer tires and the gate will be replaced with a new one built from 14 guage square and rectangular tubing.

For TO-Bud, the spring bushings are definitely not plastic or even nylon. They are steel with grease fittings. Those springs are definitely "Old School".

Thanks for everyone's input. If you are interested, I will post pictures of the completed rebuild. Once finished, I hope to be able to sell it for 1200 and $1400.

westcliffe01 · Jul 8, 2012

Honestly, moving the axle is no big deal. Buy some new hangers and bolts from Etrailer.com Just make sure the bolts and width matches the springs you have now. A set for a single axle should run about $20 Suspension Kit Single-Axle Trailer Suspension | etrailer.com

You want to be sure that with a load in the box and possible inclination, that a suitable load is maintained on the ball.

rasimmo · Jul 8, 2012

When you put the gate back on,even a lighter one, the sway will come back. You need to put more weight in front of the axle. In my opinion the easiest way is to move the axle back. That is pretty easy to do. A lot easier than cutting down the back of the trailer then reinforcing it so it won't flop around. Just measure from the hitch and make sure it is square so it will track straight.

JDgreen227 · Jul 8, 2012

K7LN said:
With a new gate and a floor, the sway may not reappear, or it probably will appear at a different speed. It's going to be trail and error. Different tires or remove some of the top weight might help too. Personally, I'd try the tool box idea suggested in post #4. Maybe the original owner never worried (or knew) about the sway because it was always used on back roads at 45.

Guys, not to be critical of the suggestions to add a toolbox to the tongue, but it looks rather short for installing one. Attachment below shows the toolbox on my 6X12 utility trailer, I had to use a 12" deep truckbox as a deeper one would hit the rear bumper of my truck during sharp turns. You need a minimum of at least 28 inches, preferably more, from the coupler centerline to the front of the truck toolbox. I had 22 inches of space when I originally installed a standard depth truckbox on mine and the front of the box touched the rear bumper a few times when I was backing up.

roamerr · Jul 8, 2012

2 words is all you need to know -- TONGUE WEIGHT. Add some weight on the tongue and it will track true. 10% of the load on the tongue should work. If the tongue is light I have seen 300 lb trailers make a Dodge Ram 3500 dually dance.

Diamondpilot · Jul 8, 2012

roamerr said:
2 words is all you need to know -- TONGUE WEIGHT. Add some weight on the tongue and it will track true. 10% of the load on the tongue should work. If the tongue is light I have seen 300 lb trailers make a Dodge Ram 3500 dually dance.

That and bad tires or rims. I have a 18' car hauler and it would dance my F-350 diesel around when empty but loaded it did fine. Long story short I was on my way to pick up a Corvette for a guy and was early so I stopped in a tire shop to have my tires balanced. I bought the trailer new and the tires were not balanced from the factory. It made a night and day difference plus they discovered one of my wheels was bent. Not sure if I bent it or it was bent from the get go. The installed my spare for me and less than $20 I was on my way with a smooth ride.

I called the dealer and they sold me a new wheel for $18 plus shipping and the tire store swapped it out and balanced it for free.

Chris

weldingisfun · Aug 25, 2012

The rebuild is finished and, as promised, I am sending along pictures.
Thanks to everyone offering assistance. The trailer pulls now at 70 mph without any sway. This is what it took to accomplish it:
Twelve inches was cut off the tail end of the trailer.
The swing-out and center lift-gates were replaced with gates made from square tubing. The estimated weight reduction is approximately 100 pounds.
Time involved to make it all happen was about 40 hours.

It is now for sale for $1200. We will see how that goes with this economy.

JDgreen227 · Aug 25, 2012

Enjoyed the pictures and appreciate the follow-up to the original post...thanks for doing that because I have thought now and then about the thread and wondered what your final solution was. Keep us posted on what you sell the rig for !!! NICE JOB...:thumbsup: