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Oct. 2, 2011 12:34 p.m. sevenracer New Reader

Hey,

Looking for some help with my 24' box trailer.

I had a local trailer shop service the axles (pack bearings, check brakes, new seals) and put 2 new tires on. When I got it back, I noticed a lot more sway when towing. It seems much more affected by passing semi's, and it oscillates if you are not smooth with steering inputs - noticeably more than before.

So my question is: Is there anything other than the tires that could be causing this? Any way the torsion beam axles could be out of whack (preloaded or something)?

I didn't check tire pressures before the service, but now they are all around 50-52 lbs. I think I had it set higher than that before, but not sure.

I am planning to try upping the tire pressures closer to the max cold (65psi). And I guess I'll try swapping the position of the new tires - they were put on the back on each side. I'll move them to the front axle.

Any other ideas of what's going on or what to try to resolve? Staggering tire pressures? I'm heading from Charlotte to Savannah on Thurs and need to get this under control - literally.

Thanks
Oct. 2, 2011 12:49 p.m. cwh SuperDork

Local trailer shop should have knowledge on this. They may just deny any responsibility, but they may be helpful. They really should know about how to handle this.
Oct. 2, 2011 4:01 p.m. sevenracer New Reader

In reply to cwh:

I actually already did take it back because one of the brakes was dragging. I was hoping that was the reason it was towing funny, but no luck there.

The shop was good about fixing the brake issue quickly and looked everything over again, but they didn't have a lot of ideas about the swaying issue. I'll be talking to them again tomorrow.
Oct. 2, 2011 4:07 p.m. aussiesmg SuperDork

Do you have pics of the vehicle and trailer loaded?

Does the front of the trailer sit low?

Do the wheels appear to have evenly balanced weight distribution?

Do you use ride levelers?

Is there a lot of weight on the back of the trailer?
Oct. 2, 2011 4:51 p.m. 44Dwarf Dork

What type of tire were taken off and what did you put on? Radials tow diffrent then Bias plys.
Oct. 3, 2011 7:30 a.m. sevenracer New Reader

aussie: I'm getting this when the trailer is empty. But I have used this trailer for 4 years empty and loaded with no issues, none of the weight dist. or load has changed.

Dwarf: All radials, same size and load rating.

thanks
Oct. 3, 2011 8:37 a.m. 44Dwarf Dork

Same brand? Radials do sway essayer do to the softer sidewalls. Trailer tires are a crap shoot at best these days.

I'm not a propionate of this but according to many sites if you towing at hi-way speeds air pressure should be 5psi above the sidewall presure.... One trailering site has several postings about this and one claim the MFG said so in writing but never posted back with the PDF of it. Me i run mine at max pressure listed on the tire cold. I also check by hand at every stop and fist trip of the year I'll check with my needle type pyrometer.
Oct. 3, 2011 8:53 a.m. 914Driver SuperDork

sevenracer wrote:

Hey,

Looking for some help with my 24' box trailer.

I had a local trailer shop service the axles (pack bearings, check brakes, new seals) and put 2 new tires on.

Doesn't a 24 footer have four tires? They only replaced two?

If everything else is exactly the same, my only suggestion would be to check the bearing tightness. Maybe it's sliding on the spindles.

Dan
Oct. 3, 2011 6:19 p.m. sevenracer New Reader

In reply to 914Driver:

Yep, 4 tires. The other two were replaced last year and still look good.

Upped the tire pressures, gonna drag it around tomorrow and see how it does.
Oct. 3, 2011 6:24 p.m. Toyman01 SuperDork

I usually run 5 psi over on my 20' enclosed trailer. The tires are rated at 40, and I run 45 in them. The other thing to check is the truck tires. They effect sway more than the trailer tires do on my rig. I went to a E rated tire on the van for just that reason.
Oct. 4, 2011 10:19 a.m. foxtrapper SuperDork

Yes, changing tires can create tremendous sway issues. Softer sidewalls let things sway a lot more than stiffer sidewalls. That is the likely place to check.

Since you had other things serviced, wheel bearings are possible as well. If the bearings were tight before, but are not set loose, you can get more sway as well.
Oct. 7, 2011 6:09 p.m. sevenracer New Reader

Update:

Well I tried some test runs with max tire pressures and various settings on the weight distribution hitch. No one setup seemed much different than another.

But I didn't really have any issues towing down to savannah.

My conclusion is that the trailer is alot more squirrelly when it's unloaded. I never really towed it empty on the interstate in the past 4 years.

So. Thanks for the help. Now i'Im focused on the race it the trailer!