I have a 1973 F-100. It has a 360 V8, and the transmission was replaced just before I bought it. It has a WDM-AG1, 9", 31 spline, rear end with a 3.00 gear ratio. The driver door tag says it has a GVWR of 5500lbs

I have installed 1500lbs rated load assisting springs in the rear, Electric trailer brake system, and a frame mounted class 4 hitch. The hitch is rated at 7500lbs GVWR, 750lbs tongue load, and 12000lbs distributed weight. Following that rating it says do not exceed the original tow rating on the vehicle.


What I am looking for is the rear Axle weight capacity and overall tow capacity of the truck (I want to pull a 6250lbs GVWR Travel Trailer). I don't want to break an axle or put my self and anyone else in danger.

Any input would be great Thanks

 

If your axle code is 02 you have a 3300 lb capacity rear axle. The overal GVW should be around 5000 lbs.

 

My axle code is 02J and my my Trucks GVWR is 5500Lbs does that mean I can only have 500Lbs in the truck (5500-5000)?

 

No, that means the weight of the vehicle shouldn't exceed 5500lbs. Example: Say the EMPTY weight of your truck is 4200lbs., that means you can carry 1300 lbs of cargo, passengers, and fuel. (5500 GVW - 4200 empty weight = 1300 lbs cargo capacity.
Empty weight is what the truck weighs with NO passengers, NO cargo and NO fuel.
Also, the "J" in your axle code means w/ power steering

 

Not to trying to be annoying or anything but do you think that my truck can pull the trailer I mentioned. I am new this whole trailer/payload capacity stuff.

I have asked Ford dealers and many trailer and camping shops. All of them either contradict each other or say the truck is too old to give me the answer. I have email Ford Motor Co still waiting on their answer.

 

Not to rain on your parade but I don't think it would work very well. I looked up the towing capacity in my owners manual (I have a '73 F100 too). It looks as though yours isn't properly equiped to tow that much weight. For 6250 lbs Ford recomended an F250
w/ a class IV hitch with 7500 GVW and Heavy Duty tow package. It also recomends an automatic transmission and 4.10 gears.
Yours will physically pull the trailer but with 3.00 gears I would expect acceleration to be something less than stellar. Any hilly or mountainous terrain would be have to be avoided. I think the cooling would be marginal at best and going up a hill will probably lead to overheating.
Again, I don't want to rain on your parade but I see problems pulling that kind of weight over any substantial distance.

 

For your setup the maximum tow capacity recomended by Ford is 5000 lbs and that's if you have the heavy duty tow package and 3.50 gears,

 

Thanks for all you info, I will begin looking for a 4.10 rear axle. Do you know by chance if any modification will need to be made to make a 4.10 rear end work?

 

With a Ford 9" changing ratios is as simple as finding a center section with the right ratio, dropping the old one and puting the new one in place. You just have to know whether you have 28 or 31 spline axles. You can tell that if you have the rear ID tag. That's a small metal tag that is held on to the rear by one of the bolts, usually about the 5 o'clock position. It will have a code on it, something like WDM-AG1 this can be decoded and you can figure out which axles you have. You can also pull one of the axles (easy, not a big deal) and count the splines.
Not too clear but this is what the ID tag will look like

 

Is there and difference in the body itself between the 100, 250, 350?

What I am wondering is if the factory towing capacities are determined only by equipment (ie suspension, gearing, axle strength, cooling and so on), or is the trucks bodies them selves were also built different allowing the 250 and 350 to tow more?

 

Thats pretty much the difference. Brakes are heavier duty as well.

 

The bodies are all the same, it's the equipment that makes the difference. Heavier duty axles, springs, brakes, cooling, lower gearing, etc.