Oh, forgot to use my 1996 Suburban's rear axle as an example
GM purchases this axle assembly from AAM.
AAM rates it at 10,000lb GAWR. GM rates it on my Sub and the 1 ton dually of that
year at 6,000lb GAWR
Why and what is/are the limiting factors/components/etc ???
We will never know as outsiders to their Product Design Team. Nor will they
ever provide that info, as I'd guess they consider that company private and
competitive advantage on how they do things
My front axle is rated 4,250lb GAWR by GM. Ordered it with the F60 option (snow
plow prep package) that has 1 ton torsion bars. The 1 ton dually 4x4 has its
front axle rated around 5,400lb GAWR
Should I take the AAM 10,000lb GAWR for mine? Then the 1 ton dually's 5,400lb
as mine also?
That would be 10,000 + 5,400 = 15,400 GVWR?!?...nope I know better, but do
claim, tongue firmly planted on cheek, my 3/4 ton Sub as a K3500.... :)
PS...also forgot that braking ability (repeated on incline, at high temp, etc, etc)
is another mandated performance item from the regulatory agencies. Maybe the
brake sizing for 'that' GVWR can not meet federal spec with higher weights
on it's back...