Sway problems
2015 F250 crew cab short bed 4x4 diesel -8650lbs (front 4900,back 3750) 35”x 12.50 x 18 (12 ply toyo) 2016 keystone impact toyhauler - 10,600lbs loaded, 1550 tongue weight Curt WDH 17501 series w...
Forum Discussion
Wscott52 wrote:carringb wrote:
What tire pressure are you running on the truck. Since you're running a considerably wider tire than stock, you should be running a lower PSI in order to maintain uniform tread contact. Especially if those are M/T tires, because if you run max PSI, they'll be riding on the center tread blocks only, which have zero lateral stability.
They are AT 12 ply 80 lb but have them at 70?
Still very much too high. Your tires area rated at 3,630 lbs each at 70 psi.
Best thing is to weight your front and rear truck axles when loaded. For now, let's assume you have the WD adjusted per Ford's spec, where half the front-end-lift is restored when you have the bars hooked. This will put about 2,000 pounds on you rear axle, in addition to your 3,750 empty rear axle weight. This will put your loaded weight about 5,800 pounds. The Toyo load chart for your tires indicate they can carry 2,910 lbs each @ 50 psi. Running at ideal pressure give you the best road traction. Sometimes it works well to add another 5 psi for a high center of gravity, but that's not the case with a bumper pull trailer.
Here is the Toyo inflation chart. Your tires are at the top of page 7:
https://www.toyotires.com/media/2125/application_of_load_inflation_tables_20170203.pdf
That adjusted PSI will trip your TPMS light. Some dealer will adjust it, some won't. Most folks just spend the $20 for a lap-top interface, and make the change in ForScan. But for a new truck under warranty, I'd try to get the dealer to do it first.
As for the trailer, low psi will also make it unstable as the sidewall flexes. But I think think 50 psi is low enough on its own to cause all your issues. But it could very well be part of the problem, along with your over-inflated truck tires.
