WD hitch school

[schmism]

Ok so i brought home my very first WD hitch for the back of my new E350.

While there are many vids out on youtube to document how to setup your WD hitch (even one for an E350) they all seem to feature a fixed tongue weight trailer (aka RV) So setting head tilt and bar tension (by takeing measurements on wheel wheels of the tow vehicle) seem to be a constant every time.

But how do you make said adjustments when your towed load may vary in weight and therefore vary in tongue weight.

One time i may only have 5000lbs behind me (3K payload and 2K trailer) vs others were i may have 7K behind me and perhaps even 9 or 10K.

Tongue weight would (in theory) change from 500lbs to as much as 800-900lbs Obviously the more tongue weight the more squat to the rear of the van and more bar i need.

Without a WD hitch one would get used to gauging tongue weight based on the amount of squat on the tow vehicle. So if i packed on a 400lb implement on the tongue of the trailer i could still set the right amount of squat based on how far i drive on to the trailer to achive the right tounge weight.

but with a WD hitch that seems to all go out the window as bar tension would seem to change every time your tongue weight changed.




in short do i have to "setup" the hitch everytime i come up with a different combination of loaded items on my trailer?

 

[Runner]

I'm a complete newbie to WD hitches myself, but my plan is to just eyeball it and change which link in the bar chain I use, based on the weight (choke up on it for more weight, back off for less). I'm sure there is a more scientific way to do it....

 

[Dmace]

Set-up your hitch for the average tongue weight (around 700 lbs in your case) then put a small colored zip tie on that chain link. If your weight is less, set the chains 1-2 links longer and if it's more tighten up the chains by 1-2 links. The head tilt shouldn't change enough to need adjustments unless your changing tow vehicles. This is assuming you have a "chain" style WD hitch like the one Runner pictured above.

 

[schmism]

so after 3 hours of futzin around with the hitch, ive got it setup (i think)

One odd thing came up.

I got things adjusted and went to clip up the chains (yes mine has chains) and the right side on link 7 i could almost do by hand by just rotating the chain holder up. The left side on link 7 required a cheeter bar as seen in setup vids and had significantly more force on that chain.

What would account for this? (other than a difference in the length of chain)

 

[Runner]

A picture might help.

I think the bars can be bought in different spring rates for different tongue weight situations. Are you sure the bars are the same rating?

Is it possible that the hitch is mounted at a slight angle (left to right) on the tow vehicle?

Could the trailer tongue be bent/warped?

 

[timswi]

A picture might help.

I think the bars can be bought in different spring rates for different tongue weight situations. Are you sure the bars are the same rating?

Is it possible that the hitch is mounted at a slight angle (left to right) on the tow vehicle?

Could the trailer tongue be bent/warped?

Yup..Trailer has to be level and the weight even when setting up WD ...At least the first time.

 

[Rancher Ed]

More than likely they are just not on flat ground. If the tariler and the tow rig are not level relative to each other (the trailer tilted to one side more than the tow rig) one side of the tongue will be higher than the other making it harder to attach that sides chains.

Ed

 

[mbrule]

A picture might help.

I think the bars can be bought in different spring rates for different tongue weight situations. Are you sure the bars are the same rating?

Is it possible that the hitch is mounted at a slight angle (left to right) on the tow vehicle?

Could the trailer tongue be bent/warped?

Not being perfectly straight, and / not level, will cause more force on one or the other bar....

 

[schmism]

Ya i took it for a drive around the "block" and afterward it seemed to have evened out.

A lesson in figuring out tongue weight. (set at just shy of 600lbs)

hears the preliminary setup

 

[Skyco]

re: different amount of effort for each bar, the 2nd bar to go up is always easier than the first since it takes a big portion of the weight. So did you try them in different order?
BTW I've never fooled with the head tilt on many hitch setups over the years..if the ball isn't the right height raise or lower it on the drawbar. I only use adjustable drawbars for this reason. I only have ever needed to pick a different chain link to adjust.
I once warned an elderly gentleman out west at a gas station that his setup was wrong and he may lose his brand new travel trailer....the shop that did it put so much back tilt in the head it looked to me like the coupler was about to pop off the ball at any second. He didn't have a clue nor did the installer apparently. 1 nice dip into a parking lot and the coupler would have exceeded how far it could go on the ball, either something bends or worse it pops off.

 

[Gl33kl]

A couple of links below to threads others may find of interest. I had saved these links while completing my set-up. Not so applicable to the tension/set-up discussion, but with a subject line like "WD Hitch School" this may get some looks. Lots of photos, links and good discussion in both - they've helped me out a bunch.

http://www.tractorbynet.com/forums/trailers-transportation/104707-about-weight-distribution-hitches-pics.html

http://www.tractorbynet.com/forums/trailers-transportation/183631-weight-distributing-hitch-dump-equipment.html

And just a note on head tilt. I set up ball height & trailer hitch (height on both is adjustable) for a level ride with a full load and still needed to adjust head tilt slightly to allow adequate clearance between the bottom of the trailer frame and the WD bars. I could see too much tilt being a problem though, if used to compensate for mis-matched ball/trailer tongue height.

Hope this helps.
Greg

 

[dstig1]

Keep in mind that just because you have the WD hitch doesn't mean to always need to use it. If you are pulling the low end that you posted (~5k) then there is no need for it and you can leave the bars off and just pull in conventional mode (Weight Carrying is the technical term). Set the bars up for the mid range of where you need it (in that 8-9-10k range), or work up a couple different set points for different loads as someone else noted.

 

[Highbeam]

I use WD systems for towing an RV and my equipment trailer with an F350. Max trailer weights are under 8000 so I have plenty of truck.

Often times I have to tow an empty flat bed to go pick up a load. I don't need the WD bars but taking them off and stowing them is a PITA with all the grease and everything so I just use the loosest link. That's the only time I use a different link for the bars.

The WD system automatically adjusts for different tongue weights to some extent. Figure that additional tongue weight will try and push the ball down harder. Well, that means that the chains will pull on the spring bars harder which means that more weight will be transered to the front axle. The spring rates of both the WD bars and the truck's suspension will make up for the additional tongue weight mostly. True, it is not perfect but enough of the new weight is adequately distributed to allow you to set it and forget it.

The tilt of the hitch head is adjustable so that you can have level spring bars. If your head has to be tilted way back to some extreme angle then you have the wrong spring bars and need heavier ones. When you have done your job right on the tilt, you should have two links hanging and spring bars level with the ground while enough tension is on the bars to properly distribute that tongue weight.