--- The gist of the quotes you agree with imply that a 900# weight gets distributed roughly in thirds. You never stated that in your original explanation and that is what confused me.
Thomas,
You're twisting my words. I said, "I have no major disagreement with the gist of either post." Lets try using some numbers. Take all the dimensions from my diagram and add your 900# tongue weight.
Back the ball of the Burb under the coupler and raise the jack. What happens to the Burb's axle loads?
Rear axle load INCREASES by 1350#.
Front axle load DECREASES by 450#.
What happened to the "tongue weight"?
Nothing. The coupler still is pressing on the ball with a force of 900#.
Well, the loads on the TV's axles INCREASED by 1350-450 = 900#. Where did that come from? Some trailer weight must have been transferred from somewhere.
Nope, the 900# on the axles simply results from a relocation of the 900# reaction which previously was provided by the tongue jack. The loads on the TV's axles have changed, but the "tongue weight" has not changed.
Now, we are not too happy about the INCREASED load on the rear axle and the DECREASED load on the front axle. So, what can we do about it?
Well, we can install a WD hitch with 30" bars and tension them to 1000# each for a total of 2000#. This INCREASES the front axle load by 612# and DECREASES the rear axle load by 912# giving
TV front axle load = -450 + 612 = 162# INCREASE
TV rear axle load = +1350 - 912 = 438# INCREASE
This means the total load on the TV now has increased by 600#. Before we tensioned the WD bars, the total added load on the TV was 900#. What happened to the other 300#?
It was transferred by action of the WD hitch to the TT's axles. So, of the initial 900# added to the TV, we now have
162# = 18% on the front axle
438# = 49% on the rear axle
300# = 33% on the TT's axles
If we wanted to shoot for the 1/3-1/3-1/3 "distribution", we could increase the WD bar tension from 2000# to 2300#. This would INCREASE the front axle load by 703# and DECREASE the rear axle load by 1048# giving
253# = 28% on the front axle
302# = 34% on the rear axle
345# = 38% on the TT's axles
and this is about as close as you can get to equal thirds with the assumed dimensions.
So, have we distributed the 900# "tongue weight"?
Nope, it's still where it was to begin with. But we have re-distributed the 900# load which was transferred from the tongue jack to the TV's axles.
Hope this helps.
Ron
