John wrote:
Often times GVWR is limited to less than f+R awr due to brakes. We know the frame is designed for the full rating at each end, so there is something else limiting it.
There are times where exceeding GVWR isn't a big deal, and other times where it is. It really just depends on what your using.
Actually brakes on a vehicle ( our trucks or trailers) are determined by the axle rating;
NHTSA says this about components of the GAWR:
"Gross Axle Weight Rating is the rated load-carrying capacity of an individual axle and wheel assembly. (It represents the load that may be steadily sustained by the components in the system; i.e., tires, rims, hubs, bearing, axles, brakes, suspension, sub frame, etc. with the GAWR limited by the components with the lowest working rating".
This is one big reason dot allows us to use the sum of the vehicles axle rating as the vehicles GVW (if required) and another reason GVWR doesn't determine how much load the truck can carry safely/legally.
Many times its not the tires that is the weak link in any size truck. looking at tire/wheels/spring rate spec on Fords 150/250/350 trucks shows the wheels with the lowest rating on some trucks and others its the spring pack.
