Towing dilemma!! major trailer sway

Ok the jist: 07’ Taco TRD Sport 4dr short bed 4x4.

Issue: while driving with 12’ utility trailer/landscaping trailer however you want to classify it as, i am getting major sway above 40mph. Now ive had this trailer for a LONG time and towed with different trucks and no issues even this Taco.

Recent changes: both sets of leaf springs on trailer were changed out but i also did the “add-a-leaf helper spring” kit to the Tack also to help with sag and load. Didnt have too mich excessive sag, but saw a sale and figured “why not”. So those are the only two changing factors with the new towing condition. My question is, is it possible the

$190 Add-a-leaf kit for 1995-2023 Toyota Tacoma - 21.5" Short AAL Set with Isolator Pads and Square Bend U-Bolts

Add-a-leaf kit could have made the rear too rigid and causing the sway? When i say sway, if i am not paying attention and throw it into Neutral and coast quickly it will tip the truck.

 

Highly unlikely it's caused by stiffening the springs. It is possible that the axle went off alignment when you replaced the springs, and the crabbing combined with the wind is causing it to sway.

Let's start with the stupid questions.

Does the trailer sway when empty or loaded, or both? Have you tried weighing down the front of the trailer to see if it eliminates it?

 

My 1st guess is improper loading.

https://www.youtube.com/watch?v=6mW_gzdh6to

 

If there's more weight behind the trailer axles than there is in front of them, you're more likely to get the sway you're experiencing. Try loading the front of the trailer a little heavier next time.

 

Ok so to clear a few things up, ive been towing ATV’s with this trailer for like 9 years now. Proper weight distribution isnt an issue and i also am aware of the trailer pitching towards the truck and so i have a drop hitch for that since the trailer sits so low. Tires are brand new and have proper pressure. I have not tried the trailer empty to see if it swings with it empty. I did not do the work to the trailer, it was done by my wifes grandfather on his own in his garage (who technically is the owner but im the only one that uses it ever).

It never swung before and the only changes were what i listed above to my truck and the trailer in the same time period.

 

Definitely check it empty, and also measure the distance between the axle and front spring mount. The more I think about it, the more it sounds like axle alignment to me.

 

I'm betting you were right on the borderline for tongue weight. Then you raised the truck. That raised the trailer tongue which shifted some of the weight to the rear. For evidence of this, pickup bed trailers make shitty trailers. If you lift the tongue of a pickup bed trailer up in the air, it gets to a point where the back of the bed hits the ground and it stays there. That's because the weight of the trailer shifted rearward and even though the tongue is now 5' off the ground, you have negative tongue weight. I have seen plenty of trailers sway all over the road because they loaded the refrigerator last, or they piled 5 bags of wood pellets in the back of an otherwise empty trailer. Either weigh your trailer and weigh your tongue weight, or just add more tongue weight and see if the problem goes away.

 

^^^^ This. Been towing for over 30 years and not enough tongue weight will cause sway more than anything else.

 

Does it look like your position has moved forward? This would change the tongue weight percentage. If it were me I would check the tongue weight and axle fore-aft positioning.

 

Might be easier to troubleshoot if you post a picture of the rigs together with the trailer loaded.

 

Weight distribution (tongue needs to have most of the weight), tire type and inflation.

Brake controller if the trailer has brakes. This will only help to STOP the sway. You can activate the trailer brake independently of truck.

 

the OP did NOT have issues until he changed the springs

no less if they were worn he should have install NEW wheel Bearings set properly 9 NOT mentioned )

new springs on shackles may not be aligned........only takes a fraction to be Out !!

loose wheels bearings will do it EVERY time !!

poor tongue weight doesnt help .................

 

Im not sure if he changed the bearings, i think he may have just greased them but i will inquire. Yea im fully aware of loading properly, did that mistake first time i took the trailer years ago and never did it again lol. Almost shit myself how bad the trailer swung that day. Would a regular auto mechanic shop do work to trailers or you think i need to take it somewhere specific to fix alignment issues? Or can i put it on jack stands and do it myself since im sure i have the tools for it

 

no brake controller needed, only single axle trailer with no brakes

 

All you need is a tape measure to check the axle alignment.


Before doing anything I'd unload the trailer and throw a couple bags of sand (or something else with some weight) in the front of the trailer and see if you still have sway issues with just that weight.

 

I towed an old fridge (1940’s) and a water heater with it like 150 miles and had to do like 45-50 the whole time cuz it kept swinging and all the weight was forward the axle with the heaviest in front.
What is this tape measure method?

 

Basically, you're just checking to see if the axle is square in the trailer frame and perpendicular to the tongue. It should also be centered left to right.

 

Check all nuts and bolts for the spring swap, something may not be tight? After that, as stated above, you might have cocked the axle in the frame. Measure to see if the same measurements apply to both sides in the same places, i.e., center of wheel to rear of trailer....

 

The most accurate way to check the axle alignment is to measure from the center of the hitch ball to the alignment pin that locates the axle to the spring on both sides and compare the 2 measurements. They should be very close. To do this you may have to block the trailer up (high enough to crawl under it) and take the wheels off.

If the 2 measurements are different, then check the measurement from the axle locating pin to both spring eyes on each spring. I have seen springs where the pin is not centered between the eyes.

If the pins are not centered between the eyes, the springs may have been installed with a short end to the front on one side, and a long end to the front on the other side. That will definately cause a sway.

If that is the problem, you simply need to remove one spring, turn it around, and reinstall.

Good luck...

-Bear

 

After all said and done, the trailer owner(grand father-in-law) has become overwhelming for wanting to be in complete control of the situation with the trailer (he installed the axle badly which created the dangerous sway that didnt exist before).

purchased my own 14’ dual axle with brakes, added brake controller to the Taco and she towed w/o sway yesterday.
I have new issues but i think a WDH might solve them from what ive read so far