JRscooby wrote:
don't guess. take the truck to a cat scale, weigh it, then reweigh with the loaded trailer attached. the added weight to the rear axle is your tongue weight
Is a false statement because you can take the same trailer, with the same TW, hook to different TV and get a different change in the weight on rear axle of TV. A short wheelbase, gas powered TV with long overhang will transfer more weight than a long WB with heavy engine and the ball closer to axles.
A WDH can transfer the weight back to steer, adjust so only the amount of TW can be added to rear TV axle, but the TW must be known if somebody wants to set it like that.
All it takes to make it true is to rephrase "rear axle"
with "both truck axles weight"
But CAT scales usually have 200 lb jumps so that will bring big error margin.
Why not use bathroom scale with lever board?
Wait, that would bring us back to 4th grade physics, ... or was it algebra?