Need help with hitch (tongue) weight...Simple question

[guppydriver]

I know my current tow vehicle is a Tundra, but I have a PB on order with Granger so don't be too mad.

I have a question regarding my hitch weight after a couple Cat scale passes. First pass was my tow vehicle only. Second was TV plus trailer (boat in this instance).

I noticed the drive axle on the second pass was 1060 pounds greater than the unladen drive axle weight. At first I assumed this was my hitch weight.

However, I also noticed that my steer axle weighed less during the second pass by 260 pounds. I assume the force exerted by the trailer transferred some of the steer axle weight aft to the drive axle. In this case 260 pounds.

So is my hitch weight 1060 pounds, the total increase on the drive axle compared to an unladen truck or is it 800 pounds, the increase in drive axle weight coming exclusively from the trailer?

Sorry if it's a dumb question. Be gentle.

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[daemonic3]

I haven't done a statics problem since college but your true hitch weight (at the trailer ball socket) is what you are trying to find. That's why the easiest way is to put a tongue scale right at your trailer ball socket to weigh it.

That being said, it sounds like you don't use a weight distribution hitch? I think you aren't supposed to with boats anyway (not an expert), but this should make the math easy.

14000 (2nd pass) - 6120 (first pass) = Total trailer weight = 7880#

7880# - 7080 (trailer axle) = 800# tongue weight

This matches exactly with your +1060 (drive) + -260 (steer) = 800#, so both these methods check and balance perfectly.

The other fun part of this is the ratio of the 800 downward force at the ball to the 260 upward force at the steer axle, using the drive axle as a fulcrum. It means 260/800 is the exact ratio in distances of (rear axle to ball)/(front axle to rear axle) because the force*distance has to be equal.

 

[Griddlez]

I haven't done a statics problem since college but your true hitch weight (at the trailer ball socket) is what you are trying to find. That's why the easiest way is to put a tongue scale right at your trailer ball socket to weigh it.

That being said, it sounds like you don't use a weight distribution hitch? I think you aren't supposed to with boats anyway (not an expert), but this should make the math easy.

14000 (2nd pass) - 6120 (first pass) = Total trailer weight = 7880#

7880# - 7080 (trailer axle) = 800# tongue weight

This matches exactly with your +1060 (drive) + -260 (steer) = 800#, so both these methods check and balance perfectly.

The other fun part of this is the ratio of the 800 downward force at the ball to the 260 upward force at the steer axle, using the drive axle as a fulcrum. It means 260/800 is the exact ratio in distances of (rear axle to ball)/(front axle to rear axle) because the force*distance has to be equal.

You're good at this.

 

[guppydriver]

I haven't done a statics problem since college but your true hitch weight (at the trailer ball socket) is what you are trying to find. That's why the easiest way is to put a tongue scale right at your trailer ball socket to weigh it.

That being said, it sounds like you don't use a weight distribution hitch? I think you aren't supposed to with boats anyway (not an expert), but this should make the math easy.

14000 (2nd pass) - 6120 (first pass) = Total trailer weight = 7880#

7880# - 7080 (trailer axle) = 800# tongue weight

This matches exactly with your +1060 (drive) + -260 (steer) = 800#, so both these methods check and balance perfectly.

The other fun part of this is the ratio of the 800 downward force at the ball to the 260 upward force at the steer axle, using the drive axle as a fulcrum. It means 260/800 is the exact ratio in distances of (rear axle to ball)/(front axle to rear axle) because the force*distance has to be equal.

Thank You !!!

I loved you in Good Will Hunting by the way..

 

[JoeB]

I have a 2021, F150 3.6L PB, supercab. I tow a 22' Jayco. I have a camper shell on my truck. I added air bags to the rear axle. I have a beefy, anti sway system on the truck/trailer. I have absolutely zero issues towing full loaded travel trailer, other thana big loss of mpg average!

 

[Aron]

Another way to verify this, assuming that you have access to a Cat Scale and time to hitch and unhitch without impacting the truckers, is to park the trailer (only) on the scale and take that reading. You'd need to put the trailer axle(s) on one plate and the tongue on another plate.

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