Weight Distribution Hitches

understand that helper springs and wdhs perform entirely different functions.

Get a wdh to redistribute the load between your 3 axles. That's important if needed.

Get helper springs to stabilize the rear axle. That too is important if needed.

Neither one will in any way increase your load capacity, that's set by the manufacturer.

Helper springs do nothing to put weight back on the front axle or to reduce load on the rear axle, because they don't create any torque to counter the moment produced by the trailer.

WDHs don't stabilize the rear axle because they don't reduce lateral forces, only vertical. (The wdhs that combine sway control do improve rig lateral stability, but that's yet a 3rd function).

In my opinion, there is no reason to add either helper springs or a wdh
or anything else simply to level the TV. It's designed to squat when loaded. Having a level TV is a cosmetic issue.

If your headlights are out of adjustment then adjust them, much easier than fooling around with hitches or helper springs. If you're bottoming out then you're overloaded, relocate or reduce your load. I suppose you might want add helper springs for improved ground clearance though.

StephenH is correct, if you have helper springs of any type, and that includes adjustable air springs, you need to set them up first and then adjust the wdh to obtain the proper front axle load.

If you try to do it the other way around your wdh tension will be screwed up when you adjust the helper springs.

Heres an example of how things can go wrong. Say you have air springs and use them to level the TV with the trailer attached. Then you decide you still need a wdh because of squirrely handling. So you add the wdh and adjust it by the book to get the front axle load back up.

Oops now guess what, the TV is no longer level, it's pointing down in front. So you let some air out of the air suspension to get it back to level.

What are you left with? You just dropped the height of the ball so increased the tension on the wdh springs. So now you have too much load on the front axle and trailer axle.

So, go back and readjust the wdh one more time. Then quit fiddling around and go camping.

For myself, I never bothered with helper springs even though my Highlander squatted some with the trailer on. I wasnt worried about the squat because I knew everything was within load specs. My rear axle sway and stability was fine towing and I didn't want to change the ride and handling in normal non towing use. I didn't have ground clearance issues and never bottomed out. I adjusted my headlights down a little so they didn't blind folks with the trailer on but I could still see fine without it. Good enough for me.

OG, not questioning your explanation or scientific analysis, however it seems contradictory to recommendations from some manufacturers, namely Escape where we just purchased our trailer. They highly recommend a level rig front to back especially with the fifth wheel models. Is it because of the tandem axle configuration? I find it highly unlikely that they are recommending a level aspect for cosmetic reasons. Again, not trying to start an argument.

Originally posted by gpokluda OG, not questioning your explanation or scientific analysis, however it seems contradictory to recommendations from some manufacturers, namely Escape where we just purchased our trailer. They highly recommend a level rig front to back especially with the fifth wheel models. Is it because of the tandem axle configuration? I find it highly unlikely that they are recommending a level aspect for cosmetic reasons. Again, not trying to start an argument.

Originally posted by GlueGuy Not to be argumentative, but using a WDH on a 5th wheel is not possible; at least with all the 5th wheels I know. The load point for a 5th wheel is MOL on top of the rear axle, so it changes the weight distribution equation from a completely different perspective.

Well I'm puzzled by what you're referring to.

I looked up the Fastway E2 round bar hitch instructions on their website and saw the same procedure we've been discussing: measure the TV front axle height before and after hitching the trailer and try to get after to be at least halfway back down to before and preferably all the way back but no further.


Then after thats done they tell you to adjust the ball height to get the trailer level.

sounds right to me...