With the other topic praising the 7.3 in relation to the 6.7 and all of the different opinions in the thread, it got me thinking. Why can't the 7.3 (L99-03) pull a 5th wheel trailer rated at or above 15K lbs?

Knowing full well that the new diesel trucks have twice the HP and torque, but is it really necessary to have 800 ft lbs of torque to pull a large 5th wheel?

Is it our differentials and the gearing? The newer trucks are coming with 3:31 and mine has 3:73?

Is it our axle tubes and what they are made of compared to the new axles?

Is it the frame from the L99-03 Super Duty?

Is the transmission at fault, be it the ZF6 or the automatic?

Is it the suspension and the way it handles heavy weight?

Is it the heart of the beast being the 7.3 itself?

Maybe the brakes and pulling that weight is not the problem, it is stopping the weight?

Is it the federal regulations at the time not allowing the trucks to be rated for higher towing capacity?

The towing rating of a 2000 F-250 super cab short bed is 10K for bumper pull and 13K for 5th wheel.


What is the limiting factor making our truck not be able to pull 15K+ lbs?

 

Simple. The towing laws are based mostly on the braking power of the tow vehicle and the weight of the tow vehicle. If the truck is too light the load will carry the truck and push it during stopping and if the brakes can't handle the load of the trailer and truck then its not enough. Our trucks have terrible braking and there are little solutions. The weight is also not enough for more than 13000 lb trailer. The red neck formula to know if you can tow it is. The weight of the truck including its maximum box payload. If that number is the same or more than the trailer. Your probably good to go. Without the truck loaded I mean. So that said, our trucks plus max load is around 13k. That's what you can tow.

 

All of the above, EXCEPT the heart of the beast (the 7.3L itself). It is used in applications that move a lot more weight than 15k.

 

Just a note. I tow an 18000lb 41ft raptor with my single rear wheel. No problems. It has its own brakes though, and our laws up here allow us to tow over weight if it is an RV.

 

These trucks can tow a LOT more than what some suite wearing, granola munching lawyer who rates them says they can.
They rate them stupidly low to negate lawsuits.
Back 30 to 50 years ago when pickups had flimsy frames and junk brakes and suspension compared to a modern truck people used to tow massive loads with them frequently.
Now the lawyers all tell the truck makers to rate them artificially low.
Just like we carry campers in the box that weigh more than they say it can carry....etc

 

So, the truck is perfectly capable of pulling 15K+ lbs in a 5th wheel setup, but stopping that much weight is the problem? I thought it was going to be the axles were not built as strong or something like that in our era of trucks.

Despite the 6.7 having twice the power and torque, the main difference between the newer trucks and our trucks (in regards to towing and payload) is the braking system and the exhaust brake which makes them legally allowed to pull more because they can stop the load easier?

 

Uhm...my back seats and roof would get in the way of the 5th wheel hitch

 

 

You guys would be apocalyptic if you saw what my dad tows with his '03 7.3 f250 on the farm.

I love my 6.7 but I'm not afraid to pull the same loads with my dads 7.3 psd.

 

We would not be, I am simply trying to learn from people who have real world experiences pulling heavy loads such as you do. I am not afraid to hear about things such as this and am sure others have questions just like I do about the real limits of this truck and not what a lawyer says is the limit.

Care to share what you were referencing and maybe the distance the heavy load was being pulled?

 

I've had 25k lbs behind both of my trucks. Not technically legal yes I know.

The power on both was similar, so moving from a stop or pulling uphill has never been an issue.

However......

The new truck stops better. Period. Even when I had hawk pads and slotted rotors on the old truck, the new one still stops better and controls a load better going downhill. Old truck had trailer brakes turned way up and still took a LOT of brake pedal effort. New truck is barely breaking a sweat to stop.

Honestly that's the biggest difference. I feel much safer towing with the new truck compared to the old one if it's a really heavy load.

Remember that these are still the same trucks from 99-16 model year. Same frame, same cab, very similar driveline, etc. However as technology has changed, so has the features, power, and safety. So throughout that time they have been fed a steady diet of upgrades that have given them greater towing capacity and ability to handle those loads easier than before.

 

Apoplectic I think.

 

Pocket, did you have any suspension mods like airbags to keep the truck somewhat level? What was the distance you towed these 25K lbs loads?

Again, it seems that the limiting factor of our era trucks is the ability to control/slow/stop the load being pulled and not the ability to move the load regardless of the distance.

 

The simple answer is yes.
The trailer has its own brakes if that heavy, so it takes care of slowing itself down.
If a trailer didn't have its own brakes regardless of what year it was the trailer would push it out of control since it weighs much more than the pickup.
Take a semi, the tractor part of it is short, and does little of the braking.
It tows and stops 120,000 lbs of trailers because the trailers have their own brakes. Really the tractor part is not much if you look at a semi.
I have 3 Peterbilts that haul aviation fuel. The trailers weigh 8 times what the tractor does and it does basically zippo of the braking.
In fact often we use trailer brakes only if the road is slippery to keep the tires rolling and not just sliding off the road.
I towed homed a 5500 pound trailer with over 14000 pounds of backhoe and extra buckets on it with my f150. It was a long trip, and over a very serious mtn pass. It did great!
If my Peterbilts could handle the loads they are legally allowed to tow half as well i would be impressed.
What shocks me is how much a semi truck is allowed to pull legally.
If they are allowed to tow that much all pickups should be rated to tow triple what the manufacturer says they can.
Their power is pathetic with those super wimpy cummins diesels....the air brakes are a joke...they handle like crap....and traction is basically zero in snow trying to go up a hill.
Yet legally they are rated to gross out at 64,500 kgs, which is about 142,198 lbs when i convert it to lbs. I would guess maybe half of that would be somewhat safe. In aviation the books tell us all the time what a machines limits are....cough cough....no pilot has not exceeded that.
They tell us what a rope can lift on the hook.....the reality is the ropes can lift easily 5 times what they say and still be safe.
I can stall a 12000 pound warn winch and not even affect , forget break a rope rated for only 3,000 pounds. Put a doubler pulley block on it and still stallled the winch and could not break the rope with it.
But some lawyer decided that rooe is not safe past 3000 lbs.
Never did break it by the way.
Maybe if warn builds a 250,000 lb winch someday and i find a tree strong enough and a way to anchor the truck well enough its not just dragged i can learn what it takes to break a 3000 lb rated rope.

 

Curtis touched on the real reason. It has to do with staying legal, back before the tow wars took it above this level.

Go look at the tag in your door to see what the GVW rating is. Add 15,000 on top of that and the idea was so you'd stay under 26,001 lbs, thereby not needing a CDL to be legal. Why rate a truck at 10 million pounds if the cut off is 26,001?

Can the 7.3 trucks pull more than 15k? Sure Curtis has done it, as have others. I think I've only had 23k behind mine, so others have obviously towed more.

Of course, if you get pulled over and weighed, once you cross that magical number, it really doesn't matter what your truck can or cannot pull if you don't have a CDL.

Ford actually offers a 9,900 GVW rating on a SRW 350 (that's what I have) so that you can tow a trailer with dual 8k axles (that's what I have) and still be non CDL. It's still the same truck with all the same parts as the ones tagged at 10k or above, it's just playing the numbers game.