I know we must have a Judge, a Lawyer and a DOT officer out there among us TDR's.
Not a TDR member, but a member of RV.net wrote;
"I am a retired state police commander. I commanded a district which had the highest fine producing fixed scales in the state. In additiona I was one of 2 of the first Troops in the state to be certified as motor carrier safety inspectors. By IL statute only the ISP has the authority to conduct MCS inspections. I taught truck weight and MCS law at our academy. Over the years I weighed a lot of trucks. I also weighed a lot of RVs of various styles, not because of the law but because the RVers asked to be weighed to have their loading checked. Never ever saw any of them even come close to approaching max legal weights.
Simple answer to your question. The sticker on your truck is placed there by the manufacturer. It's like the tag on your mattress. It's required by law to tell the consumer what is in that product. After sales that sticker doesn't have to remain on the vehicle and there are a lot of vehicles legally on the road today which no longer has the sticker because of body repair, etc. The manufacturers do not make the laws. Think about this too. Do you think every Troop or weigh master out there has memorized what all the manufacturers stickers say on every style of truck made? Then toss into the mix 4X4 v 4X2, same model trucks but with different engines, same model trucks but with different axle ratings, or same model trucks but just different years. We don't care what the sticker says or even if there is a sticker. What the manufacturers put on that sticker is not law, it's just a to let the consumer know what that particular vehicle's design specs are.
The max weight laws are generally 20K on a single axle, 34K on a tandum axle and gross is 80K. These are federally mandated limits. I say "generally" because gross depends on the bridge length of your vehicle (distance between the front and rear axle) and the number of axles. The 34K can also vary depending the distance between the tandum axles. It could be more. Weight limits may also be posted less than the max on certain roads.
As an RVer you don't have to worry about exceeding the 20K single axle, 34K tandum axle, and 80K gross. There's no way you are going to be anywhere close to any of those numbers. Think about it. On your 5er you put 16" E range tires on a 5K or 6K rated axle. Your suspension and tires wouldn't handle 20K or 34K loads. And no way are you getting anywhere close to 20K on the steer or drive axle on your pickup. Your Big Country doesn't even come close to approaching 34K on the tandums. Your entire rig is likely to be about 20K total. You could not load your 5er and 2500 with enough toys to get close to exceeding the weight limits. "
I happen to have an old gooseneck deckover flatbed that I bought from an old farmer. The VIN tag was long gone. Since he was a farmer, it had never been registered and he still had the original Certificate of Manufacture. I used it to register it for the GVWR of 14,000 pounds. I could have registered it for more, but 14,000 seemed appropriate at the time. It has two 7000 pound axles under it, but there are no "tags" on the axles that an inspector could look at, I found out what they were when buying brakes and backing plates. I put the required lights on it and pulled it loaded from TX to VA then MA to WA and then loaded it again and came back to TX. Never had a problem with DOT and it is one ugly trailer.
Attention: TDR Forum Junkies 
I hang my head in shame. 
