drsteve wrote:
The axles and tires carry the weight. The air bags and springs just attach the truck to the axles. You could get rid of the suspension and the axle weight ratings would not change.
Yes, but manufacturers de-rate the axles based upon a combination of things, to include wheel/tire combo, suspension, etc.
The rear axle on the SRW 3500 and the 2500 Ram and Ford are the EXACT same (not sure about GM products, never took the time to inspect them). Ford de-rates the rear axle on the F250 because they don't include additional spacers and overload springs (suspension equipment). Ram de-rates the rear axle on the 2500 because they have coil springs rated at 6500 lbs (with 18" wheels), rather than leaf springs at 7,000 lbs (again... suspension equipment).
While air bags don't change the manufacturers rating, they most certainly do change the suspensions ability to carry the weight.
