plrgpr

2012 EcoBoost 5000 miles on truck. NEW trailer w/WD hitch. At 55-60 mph the truck shakes like it has a tire out of balance while towing LOADED trailer. Truck rides perfect while towing trailer unloaded or w/o trailer hooked up. Trailer is a 18' open car hauler. Trailer and car weighs app'x. 4500#. Truck sits pretty much level when hooked to loaded trailer. Rear squats 7/8", front squats 1/2" when the trailer is hooked up w/car on trailer and w/d hitch installed. I jacked up the trailer and spun the tires by hand and found no excessive out of round or wobble. The trailer tires are not balanced, but everything thing I have read says that you would not feel out of balance trailer tires in the tow vehicle. What do you guys think my problem is? Again, truck AND trailer are new!

gn85

What tire pressure is in the tires of the trailer?

plrgpr

50psi trailer, 35psi truck. 50psi is what is recommended on tire sidewall.

brulaz

A lot of people do balance their trailer tires. Mine are.

No tread or belt separation on tires? Trailer tires are notoriously cheap.

But, when you say " front squats 1/2" ", maybe you are lifting too much weight off your rear axle. Ford says to reduce the front end lift with the WDH by only 50%. You are reducing it by over 100% if I read you right.

plrgpr

Guess I don't follow you. The truck sets lower both front and rear. The rear sets a bit lower than the front so I don't follow how i am unloading eithier end???

brulaz

Right, you're not unloading the rear as it's still lower with the WDH.

But Ford still recommends reducing the Front end lift by *only* 50% with the WDH. Some go to 100% (completely removing the lift). If the front end is lowered at all (removing more than 100% of lift), then you are putting more weight on the front than was there without the trailer. And that's way more than what Ford recommends. I guess the truck is just designed to carry most weight on the rear.

Really not sure if this will help at all with your problem. But who knows?

plrgpr

Plz bear w/me here as my skull must be awfully thick, but I don't see how I have ANY front end lift as it is sitting lower than when trailer is unhooked????

brulaz

EDIT: Wait a minute, maybe now I'm confused. Is the front end lower when the trailer is hooked or unhooked? With or without the WDH?
Anyway ....


OK. No problem. Start over.

First, measure the distance from ground to top of wheel well on all four wheels with NO trailer.

Second, put the trailer on the ball, but do NOT adjust the WD tension bars yet. Measure the wheel wells again. The front will be lifted, the rear will sag. Calculate the difference: it's *that* front lift Ford is talking about.

Now adjust the WD tension bars so that front lift is reduced 50% (Ford's recommendation, or some people go up to 100%).

Better ?

ragerjr

Are the tires on the trailer new? The reason I ask is if the tires have been on the trailer awhile setting on the dealership lot then they may have a flat stop or a start of one. When you are empty there is not enough weight for you to feel it but when you put weight on it (pressure) then it becomes more prevalent. Just a thought. I have seen this before on some of my buddies trailers that sat for a long time.

Have you tried to pull the trailer without the WD? IMO 4500# is not enough weight for a WD. I have been pulling multiple types of trailers with multiple types of trucks for 19 years (since I was 16 and I am now 35). You should only have about 450# (10% of 4500#) of tongue weight.

brulaz

Really good point. With an open car hauler, 10% on the hitch should be fine.

And with only 450# hitch weight, the front end lift is hard to measure so setting up the WDH properly is difficult.

I would ditch the WDH.