My post about 571.120 was directed a Raw Dodge's comment to Diamond plate which says;
Raw Dodge Quote: "Thats a typical move.I was at the local fair this summer,and i seen a few trailers with 7 ton axles with GVWR tags of 15,600lbs.I asked the salesman why they were rated so high,he said the tongue weight....gives the owner a little more legal capacity as long as he is loading it right.
Diamondplate says : They do make 6 lug 6K axles but I would guess you have 5.2K axles and they are allowing 1,600# on the tongue. Not saying this is 100% true because of different tires and such.
On typical radial tired campers, boat trailers, ect this seems to be the case due to tire loading.
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Heres the new 571.120 reg : S10.2 On RV trailers, the sum of the GAWRs of all axles on the vehicle plus the vehicle manufacturer痴 recommended tongue weight must not be less than the GVWR.
my quote says :new NHTSA regs 571.120 as of 6/15/08 says the trailers GAWR must match the trailers GVWR plus the hitch weight. Prior to that date RV manufactures were installing axles that equaled GVWR minus the trailer hitch weight.
Spin it anyway you want but both GVWR has to equal GAWRs or GAWRs equal GVWR.
Guess I should have quoted Raw Dodge in my first reply. Sorry for the confusion.