Hello,
I am new to this forum and new to Ford trucks. I just bought a 2006 F550 XLT 4x4 Supercab with a 9' Rugby dump body. The front axle rating is 7,000 and the rear axle rating is 13,660. The GVWR is 17,950. I've seen other 2006 F550's with a 6,000 front axle rating and 13,660 rear axle rating but the GVWR is 19,000. What causes the difference in the GVWR? I've also seen trucks where you can simply add the front and rear axle ratings and that is what the GVWR is. Any help with understanding GVWR information is appreciated.

Also, can I load my truck to 19,000 GVWR since my axle ratings are higher? Thanks much, Matt

 

Before we start ANYTHING, a few points to be made.

1. What state are you in? Some states do things differently.
2. The GVWR on your door is the GVWR you care about. After that, very little matters.

Ok now lets get down to business. GAWRs do NOT add up to your total weight. Why? Say (in a magical land) that you put 9000lbs on a 9000lb axle and that didnt exceed any other weight limits. Well, that axle is maxed and can no longer take any more weight. You can fix this my moving the load forward or back to another axle.

GVWR is the maximum your vehicle may weigh at any one time, regardless of GAWRs.
Next you have Max Payload, and Max Tow (you have 2 tow ratings. GN/5er and bumper).

Example with easy numbers:

Trucks Total weight, unloaded: 5,000lbs
GVWR: 20,000
GAWR: 15000 each
Max Tow: 15,000 lbs.

Ok so lets say you load up your truck with fuel, you and some gear. Now youre sitting pretty at 6,000lbs. You have 14,000lbs of GVWR left to use. Your GAWR and Max Tow are higher than that, but to be DOT legal, you may only add 14,000lbs more weight.

Think of it like this, you are only as strong as your weakest link. The lowest weight rating is the limit. Once you hit one, youre done.

Another weight rating to be aware of is pin weight. Say you can max out at 1000lbs of pin weight, thats probably going to be the limit for your load right there.

 

Theory is nice and good sample above, but on practical side you don't have much control in loading front axle. With the way those trucks are build almost all payload goes on the rear axle and only stuff like forklits with one heavy end would allow you to transfer some cargo load to front axle.
On good side, the axles can take overload just fine as long as you have tires rated for it.
I do have Dana 80 on my F450 and had the rear axle at 16k more than once.

 

These questions come up quite a bit here, and it's always a big debate.

First, your GVWR is determined by an number of different things, not just whether its an F-350, 450, 550, etc. Engine, transmission, wheelbase, gearing, brakes, and other things are all considered when Ford sets the GVWR.

If you loaded to 19000 lbs, you would be overloaded by 1050 lbs. I think it's pretty safe to say thiswouldn't hurt the truck at all. However, I would research your local laws on the legality of doing this.

Being that this truck is considered a commercial vehicle, I would recommend not going over the 17950 GVWR just to save yourself any potential problems with the DOT.