Sway problems

Add a sway bar for $100.

carringb wrote:
Also - I just re-read the numbers in the original post. It looks like you're fully restoring front axle height. On heavy pickups, this can leave the rear axle too light. Might want to take a out a washer or two, to slightly reduce how much weight is being moved to the front axle.

his rear axle is still dropping an inch and a half. so it has plenty of weight on it.

Sweet!!
Now just make sure those trailer kings are rated for speeds above 65mph most that I know of are not so watch going that 72 with 1 finger on the wheel. I have the Carlisle Radial HD's that are rated for 81mph and in the 3 years I have had them now have been great tires.

OK
Just returned from a 40 min hwy test run.
Truck tires @ 60 psi
Trailer tires up to 80 psi
Adjusted the WDH to allow for 1/4 rake nose down on trailer.
Drum roll .................

Boo ya. Cruise at 72 one finger on steering wheel. Flip flop is gone!
Squishy trailer tires appear to be the issue, in looking for the problem i appear to have skipped the smallest detail and had gone straight to all the big issues.

I would post a pic but can’t figure that one out right now.
I want to thank each of you for your input, it helped me out of my tunnel vision.
Sincerely
Wscott

In my experience, I've seen 4 primary causes of trailer sway.
1. downhill and trailer is pushing the truck, but this is downhill only and exaggerated by other less than ideal conditions.
2. Soft trailer tires.
3. Not enough tongue weight. (Doesn't appear to be the case here)
4. GROSSLY overloaded tongue weight on the truck (not the case here).
Certainly there are other nuances that affect sway too but I think these are the more typical ones.
(Like axles too centered on trailer, enough tongue weight, but a disproportionate amount of load behind the trailer axles will make the tail wag the dog.)


OP, agree 50psi in the trailer tires sounds very low and squishy trailer tires will cause or exaggerate sway.
Presuming your 80psi tires are 15" on 5200lb axles (just a guess unless your trailer is overbuilt), you should be near max pressure for the load.
Also, have you tried towing without the wdh or taking most of the weight distribution out of it to eliminate that variable?

Agree, that tongue weight and truck setup should tow fine.

twodownzero wrote:
Wow, this one is all over the place. Do not drop your truck's tire pressure to 55, especially on the rear axle. That is dangerous.

It sounds to me like you simply don't have enough tongue weight. Load it heavier. The sway will go away with enough tongue weight. Trying to look for other solutions might work, but adding tongue weight is sure to work.

Dangerous at 55psi? how?
OP says 1550lb tongue weight, so from the info given....avg big truck = 3000-3500lb empty rear axle weight + 1550lb tongue weight (which he's actually pulled weight off of with the wdh), so about 5000lbs on the rear axle and what's the tires good for at 55psi? Over 300lbs/tire.
This assertion is contradictory to your next statement of not enough tongue weight. Again OP measured trailer at 10,600 and tongue at 1550lbs. Sounds sufficient doesn't it? How much tongue weight should a 10k bumper pull have?

twodownzero wrote:
Wow, this one is all over the place. Do not drop your truck's tire pressure to 55, especially on the rear axle. That is dangerous.

It sounds to me like you simply don't have enough tongue weight. Load it heavier. The sway will go away with enough tongue weight. Trying to look for other solutions might work, but adding tongue weight is sure to work.

No. It's not dangerous. Too much tire pressure causes instability. That is why every tire manufacturer, including Toyo who makes the OPs tires, publishes load inflation tables. His current tires are nearly 20% wider than stock, so the factory tire pressure are completely irrelevant.

He has 15% tongue weight now, so that is not his problem.

Hi JR !

Nice to meet you

You are the first one here to understand trailer tongue orientation and trailer caster here on this forum !

Take care (system won't allow me to post a PM for some reason)


Ben

JRscooby wrote:
Is the trailer nose high when hooked up? This can change the caster, make the trailer refuse to track. Of course, that would happen at all speeds, but faster would put more side force on the TV...

Wscott52 wrote:
Just bought it 6 weeks ago.
5 hours home .. scary
60 mile away test camping weekend
And this last weekend 120 miles away is all we have done.

You mean the trailer was MT when you had issues?

carringb wrote:
Also - I just re-read the numbers in the original post. It looks like you're fully restoring front axle height. On heavy pickups, this can leave the rear axle too light. Might want to take a out a washer or two, to slightly reduce how much weight is being moved to the front axle.

Ok let me do the air pressure test then if that doesn’t solve it i will move to WDH
TY