Hitch Ball Height

[RivetED]

I am trying to set the proper hitch ball height for my tow vehicle. Is the 17.75" hitch ball height (listed in the Airstream manual for our model) the starting point height for the actual hitch ball when mounted on the truck?
The hitch's instructions say to add 1/16" to actual hitch-ball height for every 100#'s tongue weight to get target hitch-ball height (approx. 700#'s=7/16"+17-3/4": tot. 18-1/4").
Also, does anyone know how important accuracy to within a 1/16th" or 1/4" is?? That seems to be an impossible tolerance to achieve with holes spaced 1" apart! If 'off' should I favor higher or lower??

[Leipper]

Holes 1 inch apart is telling you that you're okay within a half inch or so.

First thing to do is to measure (while on level ground) from ground up inside the coupler to where the top of the ball would rest when hitched up.

Second thing to do is to figure how much your tow vehicle will settle when the hitch weight is added to it. Measure fore and aft reference points (license plate bolt or something to ground) then have a few friends get in. See how much the reference points have settled.

Then adjust the ball mount so the ball is at the needed height for the coupler plus however much the rig will settle under load.

see http://sierranevadaairstreams.org/ow...tch-setup.html
for some ideas and links. Keep in mind Dallas's guidelines
"Adjust the hitch ball height to 'level' the trailer
Adjust the weight distributing bars to 'level' the tow vehicle
Adjust the hitch head angle to 'level' the bars."

[RivetED]

Originally posted by Leipper
..."Adjust the hitch ball height to 'level' the trailer
Adjust the weight distributing bars to 'level' the tow vehicle
Adjust the hitch head angle to 'level' the bars."

These steps helped me make sense of the extremely difficult to interpret instructions. Out of 7 pages of verbose & tedious instructions, the entire 'hitch head angle' adjustment is covered with a cryptic 8 word sentence.
Knowing we would return one, we bought 2 different hitchs, Husky & Valley. Different in design & manufacturing, both had the same instructions...EXACT COPIES!!!
Since a perfectly level trailer (when hitched) is not possible, I'm not sure whether to err on the high or low side.

[Pahaska]

Best to go high rather than low; however, an inch more or less is pretty much a don't care in the scheme of things.

Going high tends to transfer weight to the rear trailer tandems which, in turn, tends to decrease sway tendencies. The general rule is that the trailer should be level to one hole high.

[RivetED]

Thanks John! I've been getting the hitch ready for the rally this week and ran into these issues. With instructions talking about +/- 1/16" calculations I was concerned. On the lowest 'slot' I'm about 1.5" high from 'theoretically perfect'. No easy/simple way to go lower. I'll just set it there and go.
Thanks again, -Ed