I noticed at the new Jayco web site they have provided a link (under "Shopping Tools") to the 2011 Trailer Life Towing Guide. I don't recall Jayco providing the link before.
Within this same Towing Guide there is a section titled "Hitching Basics", and I noticed that Trailer Life Publications has yet to update their same prior mistake(s) when referencing the adjustment of a WDH. They state:
"Evaluating the proper adjustment of a weight-distributing hitch is relatively simple: The tow vehicle should maintain the same attitude before hitching that it does after hitching, measured at reference points at the front and rear bumpers or wheel wells. If it is level
before hitching, it should be level afterward, although slightly lower due to the addition of hitch weight. A level attitude means the adequate load has been placed on the spring bars to distribute portions of the hitch weight
equally to the front and rear axles. If the rear of the tow vehicle sags after hitching, then the spring-bar loading isnít adequate."
Well, for one thing the old standard of actually getting "equal squat" ("same attitude") out of most newer TV's suspensions when using a WDH is long gone. Most
TV manufactures recommend that the front suspension be returned to it's unhitched height, not lower.
The article's reference to "distribute portions of the hitch weight equally to the front and rear axles" is falling short of being accurate as well.., weight isn't distributed to the rear axle, it's removed. They also don't mention anything about weight being distributed to the TT axles.
Also, most TV suspensions today will incur a little rear sag (1"-2") and attempting to remove the sag via the WDH may overload the front suspension creating handling and steering issues.
Oh well, guess I can get a little picky when it comes to a publication like Trailer Life continually re-printing important hitching information that contradicts what TV and WDH manufactures recommend.
I feel better now
ps: Jayco Towing Guide link: http://www.jayco.com/pdfs/DigitalTLTowGuide2011.pdf