[Cracker]

Good discussion - but Nick has forced unpleasant memories of all-night sessions doing my Statics and Strength of Materials homework at the Univ. of Florida. In my own case I use 1,000 lb bars - no sway control - with 900 lbs on the hitch - measured with a Sherline scale. Unloaded my truck's front axle weighs 4,400 lbs and the rear axle weighs 3,960 lbs (---notwithstanding a fixed load in the bed.) Loaded, the front axle unloads 200 lbs to a net 4,200 lbs, the rear axle goes to 4,900 lbs, and the trailer axle reads 7,400 lbs. See the rig configuration below. I'm real happy with this setup but recently I was made aware of a factor that I had previously overlooked on my OEM GM hitch. i.e. - the hitch rating is reduced to 7,500 lbs capacity in a dead-load configuration, vs 12,000 lbs with equalizers. You have to look at the placard on the hitch to find this figure since the GM manual only addresses sway control with reference to the 7,500 lb figure. My primary use of the equalizers is to provide a cushion between the TV and the trailer - which they do very nicely. The 900 lb hitch load is within the dead load capacity of the hitch (---which, of course, goes to 1,500 lbs with an equalizer hitch - a change that would appear to be reasonable ---) and well within the rear axle capacity of the truck. What bothers me is that, by the simple incorporation of the very lightly loaded equalizer bars, the hitch towing capacity goes from 7,500 lbs to 12,000 lbs! With full understanding of the basic moment and torsion factors involved, what gives lightly loaded equalizer bars the ability to increase my towing capacity by 4,500 lbs??? I know that others have experienced failures with the OEM GM hitch and now, I'm personally beginning to question its design! My thinking is that the hitch should be capable of handling 12,000 lbs - with or without load equalization - subject only to the dead load restrictions.