Atlee

I have a 2014 F150 XLT, Supercab, 4x4, Max Tow and HDPP (which includes a 3.73 rear and 8' box). My trailer is a Jayco Jay Flight 23RB, with 6500# GVWR. In the summer of 2018, I took this combo on a 8900 mile drive to the Rockies (NM, CO, UT, ID, WY, MT, and SD). This combo was as stable on the road as possible. 99.9% of passing 18 wheelers would not wiggle the combo and it took high winds to move the front end of the truck. The tires were the OEM BF Goodrich Rugged Trail T/A LT245/75R17 LRE tires. They had upper 55K miles on them.

Thursday, I replaced those OEM tires with BF Goodrich All Terrain KO2's, LT245/75R17 LRE tires. Friday I pulled the exact same trailer (possibly a little lighter than my cross country trip) up to the Virginia mountains from Richmond, VA. All of a sudden, I had near white knuckle situation with any passing vehicle, and moderate winds were playing havoc with the front end.

I have a Blue Ox Sway Pro hitch with 1k bars, which I got from the TT dealer and it's the same hitch I used for the Rockies trip. Also, as during the Rockies trip, I used the 9th link when hitching the WDH.

Any ideas on what could have caused such a radical change in handling? BTW, I was using the Ford recommended tire pressure on the door jamb of the truck, 55# in the front and 60# in the rear, which was the same amount as on the trip to the Rockies. The tread pattern of the new tires is exactly the same as the OEM tires, however, the KO2's have a much bigger, more aggressive shoulder on the tread.

Would adjusting the chain length on the WDH made much of a difference? Could airing the rears up to 65# when towing make much of a difference? By the way, after dropping off the trailer for some warranty work in Raleigh, the truck drove in a very civilized manner coming up I-95 last night.

And one other thing, I've noticed there is some rubbing when driving on uneven ground and having to make extreme turns. This didn't happen with the other tires.

Gladehound

Most likely the front of the trailer was loaded too lightly. Did you weigh you tongue each trip?

Skwerl

Too little tongue weight in the trailer. You can't load your heavy chit all at the back. Always try to load the trailer 60/40 biased toward the front of the trailer.

acdii

Scale it, that will be the only way to know if you have enough tongue weight. If you set it up correctly, the front axle should weigh pretty close to the unhitched weight. Do that and it will tow like a dream.

Atlee

Trailer was loaded basically the same as it was before the new truck tires. Before new truck tires, everything was good. After new truck tires, everything not so good.

Plenty of tongue weight. That ratio didn't change after the new truck tires were put on. If anything, the tongue weight has always been on the heavy side, close to 15.5%. Certainly no where close to 10%. Trailer load didn't change at all. Had about the same amount of water as normal. About 40 to 45 gallons.

I have scaled it, just not since last year before our trip to the Rockies. Nothing changed WRT the truck and trailer since the last time I towed it in April of this year, and last Friday, except for the new BFG All Terrain KO2 LT245/75R17 LRE tires that were put on last Thursday. It used to tow like a dream, before the change in tires.

Sweetlou

Are the new tires the same height as the old ones? If the new ones are taller, than the truck would be taller causing the front of the trailer to be higher in the air causing sway?

Also, check your hitch and make sure nothing loosened up.

Lou

acdii

Obviously the setup has changed if it no longer handles as expected. Guessing that weight hasn't change won't correct the issue. As Lou mentioned, different tires can affect setup, and running over a scale will tell you right away if something has changed without having to tear it all down and starting over.