Help! CAT Scale Weights Not Adding Up

I took my fully loaded Expedition Max (HD Tow) and fully loaded travel trailer to the CAT scales yesterday to get my weights. I first measured it hitched with WDH engaged, measured again hitched with WDH disengaged, and then again unhitched, vehicle only.

AXLE WEIGHTS 1: steering 3080, drive 4360, trailer 5740

AXLE WEIGHTS 2: steering 2900, drive 4620, trailer 5680

AXLE WEIGHTS 3: steering 3300, drive 3380

I determined an 840lb tongue weight by subtracting the third combined steer/drive weights from the second combined steer/drive weights.

With an 840lb tongue weight, I'm struggling to understand how my drive axle weight from either the first or second weighs could ever be more than 4220 (3380+840)??? What am I missing here?? These are all back-to-back measurements. No cargo movement or loss between measurements.

The extra weight came off the front. It was 400lbs to be precise.

Seems like your tongue weight is around 1240 lbs (2nd rear axle measurement (no WDH) minus unloaded 3rd rear axle measurement).

Deep8174 said:

Seems like your tongue weight is around 1240 lbs (2nd rear axle measurement (no WDH) minus unloaded 3rd rear axle measurement).

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That’d be 1240 *minus* the 400lbs that came off the steering axle (3300 in 3rd, 2900 in 2nd), which gives 840lbs for the tongue weight.

Why does weight come off the front axle? Because the rear axle is acting like a fulcrum, like a seesaw with the engine as one kid and the trailer tongue as the other kid. Put enough weight on one end of the seesaw and all of one kid’s weight gets transferred to the fulcrum.

AdamNeedsInfo said:

With an 840lb tongue weight, I'm struggling to understand how my drive axle weight from either the first or second weighs could ever be more than 4220 (3380+840)??? What am I missing here?? These are all back-to-back measurements. No cargo movement or loss between measurements.

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The unladen front axle weighed 3300lbs. It weighed less with the trailer attached. Where’d that weight go? The rear axle.

If you have not figured it out yet, the vehicle weight 6680 pounds, the total of your last weights. After adding the trailer, you add the two axles (3080 plus 4360, giving 7440) and then subtract that 6680 leaving 760 pounds tongue weight.