16' open tandem axle utility towing a RZR XP1000 approx 4,000lbs towing- at speeds between 45-65 i get a annoying vibration/shutter type feeling- I have balanced tires on truck and trailer with no difference- 17 3.5 eco 5.5 bed with max tow any ideas?

 

Try this, weigh the tongue, then load tha same amount of weight into the bed with the weight behind the axle and see if you get the vibrations. If so, it's pinion angle, if not its the trailer. You can add Sumo Springs or air bags to correct the rear sag which should reduce or eliminate the drive line vibrations if its the truck, If not the truck, then take a mini sledge or heavy hammer with a flat head so that it can stand up on its own with the handle vertical, jack up a wheel so that it spins freely and place the handle so it just barely touches the tire and give the wheel a spin. Do this on all four wheels, if you have an out of true wheel it will show up, and no matter how well it is balanced, an out of true wheel can cause the truck to shake. Going through this myself on a new trailer that the wheels were improperly torqued and hoping I can resolve it with reindexing and properly torquing the wheels.

 

If i put the vehicle in neutral it is fine- so i am assuming its the truck and my brother has the exact same truck and it tows fine behind his truck.

 

Yep, it's the truck alright. Check the motor mounts, that can cause it too.

 

Vibration changing when putting it in neutral leads me to believe it is pinion angle.

 

Hmm, I just towed with my 2015 3.5 with 5.5 Bed. Just got the truck a few months ago with 20K Miles. It rides smooth! Went to pull my 7x14 Aluminum Cargo Trailer Last night and it felt almost like I had tires that needed to be balanced in the rear. Got back home, Hooked it up to our jeep, pulled smooth. Drove the truck again without the trailer just to make sure I wasn't missing something, and again smooth. Hooked the Trailer Back up (Empty by the way) Its Aluminum at 1680 lbs, dual axel, and once again drove like my rear tires were out of balance.

Been Reading about possible Driveline Issues? Pinion Angles? Pretty sad actually. Bought the truck to town our kart race trailer around the Pacific North West, but not if I have to feel like the truck is going to shake apart.

Some others have been Saying to Add the RideControls?

Curious how yours is doing and if you figured anything out.

 

More than likely you have a wheel on the trailer either bent, or unbalanced. Bent as in one lug nut is tighter than all the rest. I bought a 5 x 10 utility trailer with ramp a few weeks ago and as soon as I hit 60 MPH shook the truck like I had a bent wheel in the back. Turned out none of the lugs were properly tightened, so I jacked up one side, removed the wheel, rotated it two lugs and put it back on and torqued them to 120 FtLb, then did the other side, vibrations gone.

 

Normal

 

 

Yep, bet it does too! I don't know what Ford did to the new gen chassis, but it is VERY sensitive! The wheel vibrations on the trailer travel right though the hitch to my butt. Would not surprise me in the least bit if I had hooked the trailer to an older F150 and not notice a single shake.

You can however confirm simply by weighing the tongue of the trailer and putting that amount of weight behind the rear axle of the truck by the tailgate. If the truck vibrates, then you can most certainly rule the trailer out.