Tongue Weight Rating

lbrjet wrote:
No Ron I have no link, just logic since the hitch and bars are literally hanging on the receiver it makes sense to me that they should be included against the receiver rating. This would be no different than adding a third propane tank and claiming it didn't increase the tongue weight.

Adding a third propane tank would increase the tongue weight.

Attaching a WDH to a receiver does not increase the tongue weight --
but it does increase the vertical load on the receiver.

Applying load to the WD bars reduces the vertical load imposed by the TT on the receiver.

Tongue weight is tongue weight. It doesn't change unless you change the weight of the cargo or relocate the cargo.

My logic says that, if you start with zero load on a receiver and insert a 100# WDH, you end up with 100# on the receiver.
If you then place the coupler of a 1000# tongue weight trailer on the ball, you now have 1100# on the receiver.
If you then adjust the WDH to transfer 200# of load from the receiver to the TT's axles, you now have 900# on the receiver.

The net vertical load on the receiver ends up being 100# less than the tongue weight.
The receiver really doesn't care where the loads come from, it only cares what the net load is.

The stress imposed on a receiver is largely due to the pitch-axis torque generated by the WD bars -- on the order of 4000 lb-ft for a 1000# TW.
An opposing torque of about 1000 lb-ft is generated by the downward load imposed on the hitch head. This opposing torque reduces the torsional stress in the receiver.
The weight of a 100# WDH generates additional opposing torque of about 100 lb-ft -- further reducing the torsional stress by a small amount.

Ron