I have a 2015 S/C FX4 lariat 3.5 with a 6.5 bed. I only had 400 miles on the truck and decided to put a auto spring 2.5 level kit with the inch tall block in the back. Along with that I put 295/60r20 Toyo Open Country M/T on aftermarket 20 in wheels. Now this is the first time I put mud terrain tires on a vehicle of mine and I'm guess that is my issue. I now have 6000 miles on the truck. So here it goes I currently pulled a pontoon boat for vacation and had to go 350 miles and I was white knuckling it anything over 60 mph. The truck just seemed like it was all over the road. Along with that just under normal driving it seems I'm trying to heard cats down the road seems like it drifts back and forth then when i hit a bump in the road it seems to want to kick the rear out on me. My ears are open with any suggestions any of you have. I haven't tried changing any thing back I thought I would check here first seeing a lot of you have close to the same set up I have or one of the other. Could it just be the tires or adding the taller block in the rear extending my shocks to far I'm open to hear anything so please help I love the truck and just want it to handle and ride better.

 

Did you get an alignment done after the level was installed?

 

yeah shortly after everything was installed

 

Did you run it with stock tires at all? You may be feeling the larger lugs on the M/T flexing. It should have gotten better with more miles on it.

 

This really sounds like a bad caster setting to me. I think I would try a different alignment shop.

Edit: After looking up a few things, I realize now that your problem could be a result of incorrect caster, camber and/or toe. The big clue to me here is that this problem started after you installed the leveling kit and went with different wheels and tires. So, I think your alignment is faulty.

And, I'm guessing you don't use a Weight Distributing Hitch when you're towing your boat? The tongue weight of the pontoon trailer, while probably not excessive, DOES lift the front axle a bit, which would cause a different steering "feel".

- Jack

 

Yeah but only for about 400 miles and I was so happy to finally get the truck and noticed the rear end kicking out when hitting bumps on curves but never hooked up to anything in that time.

 

Yeah you are the third person to say bad alignment job. I'll take it some where else and get done. You are also correct not using a Weight Distributing hitch. I'll post a picture of it hooked up so you can see how it was sitting.

 

So when truck is sitting with no load the rear is higher by 1.5 in and after the load was put on her on level ground the front was higher by a strong inch. Looks worse in picture but the ground isn't level where picture was taken.

 

Yup, you're taking a lot of weight off the front end, which (I think) will change the camber angle. Still, I don't see that the tongue weight is excessive, so I don't think you really need a WDH. However, if the alignment is "off", then the trailer will probably aggravate the problem.

IF (once you get the alignment squared away) you find that towing still effects the steering, then you might investigate using a WDH. When they're set up right, you won't even know you're towing, except for the reduction in acceleration.

- Jack

 

ok I also thought about adding air bags or super springs as well. Also in this picture that 6.5 bed was loaded full of luggage, coolers and everything else for vacation so that doesn't help either. But I will defiantly get the alignment checked when I get home. Thanks for all your guys help and input I really appreciate it and I will let everybody know after I try everything.

 

By the way tmanfx4, I like the look of your set up! Wheels/tires really look great!

 

I have a 2016 XLT 3.5 Eco with Max Tow,FX4 and LT tires and pull a 6,000lb loaded TT and have a Reese WDH all stock. I get a little wiggle at the rear of the camper but not much, the most annoying thing when towing is from passing vehicles and side winds. When towing in side winds of 15-30mph the entire rig (truck and trailer move a lot side to side, basically getting blown around a lot but no sway. I have tried different bar settings on the WDH. Sure would like to cure this.

 

Gadgetman, it sounds to me like possibly you have not transferred enough weight to the front axle of your truck with the WDH. The only way to know for sure would be to weigh the two axles of the truck on something like a CAT scale without the trailer attached, and then again with the trailer hooked up through the WDH at your normal tow setting. Ideally, the increase in weight on the front axle would equal the increase in weight on the rear axle. If the weight on the front is too low, you need to "shorten" the chains on your WDH to lift the rear of your truck more. (You do this by hooking the chains at a lower link.) Use the tongue jack to lift both the trailer tongue and the rear of your truck so that you can hook the chain in this way.

A less accurate method of getting the weight distribution right is to measure the drop of the wheel openings at the front and rear axles of the truck. They should be about equal, and if different, the larger drop should be in front.

But, you have a fairly large trailer behind you and it acts like a big "sail". You may not be able to totally eliminate the side to side movement in winds or from the turbulence caused by other vehicles.

- Jack

 

Something else I don't think was mentioned was to also make sure you increase tire pressure while towing, especially with LT tires. I have a set of bfg ko2's in a 275-70/18. I called bfg and they recommended 50 psi all the way around, empty. If I was towing I would probably crank them up to at least 65... And I know for me personally that the electric steering took some getting used to.. Sometimes it almost feels like the truck is steering itself. I have learned to hold the wheel straight and the steering will compensate for road crown etc.. If I try to constantly correct it seems that it feels more "squirly"... Also, I have ran the Toyo MT,s in the past, and as far as mt's go I felt that they didn't squirm as bad as others..

 

Also as far as the rear end kicking out over bumps, that's a common issue even on stock trucks. An aftermarket rear sway bar helps this from what I have read.. That's probably my next upgrade..