From what I have read and understand the factory is afraid that if someone tightens the WDH too much it could damage the frame. My Ridgeline was an RTX that came with a factory hitch. I just slide the Reese ball mount into the receiver on the Ridgeline. I feel the TM tows safer and more comfortable with the WDH.
My 2619 with even a light load would cause the rear end of the Ridgeline to sag. I have used the WDH for a year now and have had no problems and it does improve the towing of the TM. I am careful not to tighten the chains too tight. I will use number 2 or 3 link and no more. I found the following test of a Ridgeline right on target.
"Bringing It Home
Our renegade journey back home, in direct non-compliance with the Honda manual's recommendation of not using a weight distribution hitch, allowed the Ridgeline to make amends. With the weight transfer, ride levelling and anti-sway effects of the torsion bar system, the Ridgeline's towing performance was transformed, and the truck regained much of the composure it had shown while towing the empty trailer at the beginning of this test. You could still feel there was a lot of weight back there, but it felt under control at all times. The difference was obvious under windy conditions and while descending hills, where the tail no longer felt like it was about to wag the dog. We encountered heavy rain on the way back, sometimes with strong side winds, and even when splashing through relatively deep standing water, I always felt in complete control.
To my surprise, Honda's literature didn't agree. In fact, the manual clearly states that a weight distributing hitch is not recommended, arguing that it may reduce handling, stability and braking performance if not adjusted properly. To me, the last four words of the preceding sentence strongly suggest that the company's legal department had the final say on this subject. A little further, the law engineers try to keep all the bases covered by stating that a sway control system is recommended if your trailer tends to sway. I decided to go by the Honda book, but threw the weight distribution system in the trailer just in case."
Full article it is interesting. He first drove to from Canada to Florida without a WDH than back with one. The WDH made a big difference in the drive.
http://en.autos.sympatico.msn.ca/gui...umentid=635459