Rocking side to side when towing

[mep67]

I have a 2007 19ft bambi towing with an fj cruiser and pro pride hitch. I've recently noticed that when going over bumps, the trailer rocks heavily side to side. There is no sway at all, but the rocking can get pretty bad and I have to slow down to about 45 mph to get it to stop. It seems to me it might be a problem with the shocks, but I was wondering if anyone has had a similar experience. Thanks.

[kpfate]

Sounds like shock problems. How long have you had the 19ft & FJ setup?

[mep67]

About 6 years.

[Bill M.]

That sounds like a form of sway to me.

[A W Warn]

Is tire pressure correct? Soft tires could contribute.
But it seems like sway to me too. Try shifting some cargo forward inside the trailer, adding weight to the tongue, to see if it helps.

[Tim A.]

Assuming your ProPride hitch is properly set up, there should be no conventional trailer sway. It is also unlikely that the trailer's shock absorbers are responsible because the rubber torsion axle (whether Henschen or Dexter) normally does not require much from the shock absorbers.

I suspect that the single axle itself is at fault. Either it is somehow loose in its mountings or the rubber "springs" in the axle are damaged or have lost their elasticity.

Tim

[mep67]

Thanks all. That gives me a good place to start. I'll go through the propride setup again and probably have the dealer look at the axle.

[GCinSC2]

A long shot idea, any chance for a second vehicle to shadow your rig and see if they can spy on the hitches / vehicle / airstream behavior?

Safety first, just an idea or setup a go pro type thingy?

[GammaDog]

If your shocks are at least 6 years old and maybe 13, I’d change them first. I’d also set the tire pressure to the max cold inflation listed in the sidewall. Changing shocks is easy and cheap and a good step before other adjustments.

[Spaggs]

Originally Posted by GammaDog

If your shocks are at least 6 years old and maybe 13, I’d change them first. I’d also set the tire pressure to the max cold inflation listed in the sidewall. Changing shocks is easy and cheap and a good step before other adjustments.

Changing shocks may just be the trick. Also, get under your trailer and see if there are any loose bolts. A torque wrench and blue Loctite are a couple of tools to have handy.
I would not recommend filling your tires to the max. Get a calibrated dial type pressure gauge and a pyrometer. For a pyrometer, you can use anything; like a turkey probe, forehead thermometer or an industrial grade infrared HVAC thermometer like a Fluke 561, which is what I have. The key for getting the best handling and wear characteristics out of your tires is to maintain an even range of tire temperatures across the tread of your tire. In your case, filling your tires to the max may possibly give you even temps, but unlikely. Too much pressure will result in excessive wear down the center of your tread and give you a smaller contact patch resulting in longer stopping distances and worse handling when driving around corners and trying to maintaining your rig in your lane in high wind conditions.
Take a reading on the outside, center and inside tread (where the rubber makes contact with the road). If temps are higher in the center than the sides, you have too much air. If temps are higher on the outsides, raise pressure. If inside and outside temps are different, an alignment needs to take place.
You can also use the pyrometer to take temps of wheel bearings and other friction related parts to see if maintenance is order.

[ROBERT CROSS]

Originally Posted by A W Warn

Is tire pressure correct? Soft tires could contribute.
But it seems like sway to me too. Try shifting some cargo forward inside the trailer, adding weight to the tongue, to see if it helps.

^
X2
Get some tongue weight...think arrow, weight forward feathersbto the rear. Are you loading to the rear to compensate for the PPP?
Don't.


What pressure are you using? ST tires?

With our '63 Safari single axle is was much less stable with standard LT radials than it was with ST tires,(much stiffer sidewalls). No PPP, just dual friction bars with a Reese WD.

POI...a 105in TV wheelbase doesn't help.

Bob
🇺🇸

[Bill M.]

Things I would try. Get a tongue weight and see if you have enough tongue weight. I would want 12% to 15% tongue weight. Check tire pressures and for any obvious problems. Check the brakes. Try jacking up each wheel and look at the suspension reaction or drop. Looking towards a bad axlle torsion. If you are carrying a generator or something like that inside try taking it out.

Try pulling it on the ball without the Pro pride hitch. Be careful and start slow. I think you have some sort of sway situation waiting to pounce on you. Possibly from too little tongue weight? Does the trailer sit level when towing?