The question is why? But, if you have to know, the only way is to place the rig on separate weigh pads for each wheel. Those weigh pads are expensive. If you know your MT weight (on the sticker) and you weigh the rig at the CAT Scale that's all you need.
Its not like an aircraft for weight and balance. But, that is the answer.
As an example: If you have a rig that weighs 12K MT, you will need wheel pads that can measure a bare minimum of 4000lbs per wheel (4 wheels - 16K lbs. Shop them and you will run! I have electronic scales for small aircraft that weigh up to 5000 lbs (1200 lbs a wheel) of course you only use three pads - 3 wheels. Expensive enough. You could buy just one scale and measure each wheel and get an idea and should be close enough. Cost wise around $1500 -$1700 for a single scale to handle the weight but would not be accurate because the of the other wheels resting on the ground but close enough for a good cigar.
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2020 GMC 3500 Dually Denali
2020 Jayco Pinnacle 32 RLTS
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