didnt know that. maybe the air suspension has something to do with it. i cant imagine towing something that big without a weight distribution setup. i wonder how that would cause problems? basically all they do is distribute the weight over the entire axle instead of just the neck.
With weight distribution systems you not only have the tongue weight of the trailer putting load on the hitch but the cargo weight behind the rear axle in the vehicle as well. I think it was etrailer.com where I read a good explanation of this
Considering the wimpy design of the LR3 hitch (I think it 500# TW max?) and the possibility of heavy cargo in the rear of the truck I can see why they don't recommend them