Weight issues.......

[SupaChop]

I’m hoping someone can help me find a solution to my weight issue, err; I mean my truck’s weight issue…...

I have a 2004 F350 crew cab, single rear wheel, long box, 4x4, diesel w/ auto and a camper package. It is stock with 3.73 LS gears and I’ve upgraded to 285/75/R16 E series BFG AT’s (3,750@80psi) and Bilstein 5100’s.

I’m having a difficult time believing the manufacturers ratings for this rig. Ford states a GVWR for this California vehicle at 9,700 lb, leaving a maximum cargo of 1,740 lb. Ford also states a GCWR of 20k lb and a maximum trailer weight of 12,500 lb.

I would like to get a slide in with hot and cold running water now having two toddlers traveling with me and my wife. I also plan to occasionally pull my Early Bronco on an open trailer (haven’t weighed it, but I suspect the loaded Bronco and trailer come in under 6k lbs).

I ask for some guidance. Are the factory numbers overly conservative and I’m fine for a rigid slide in? I know my OEM tires had a rating of 3,415 lb vs. my current tires’ 3,750 lb rating. If needed for squat, can I increase my weight capacity by adding air bags, or am I SOL with my single rear wheel axles as the weak link?

[NickKent]

you want to carry a slide in and pull a 5k plus trailer. I would have to say that you are in dually territory. 1700 lbs for payload isn't much, and with the extended hitch you will have to use with the slide in the trailer will feel heavier and push your truck around more than it would normally.

[SmokeyWren]

Originally Posted by SupaChop

Are the factory numbers overly conservative and I’m fine for a rigid slide in?

No. The factory GVWR on an '04 F-250 PSD is perhaps overly conservative, but on your F-350 SRW it is close to reasonable. You can ignore that 200-pound penalty of the CA emissions, but otherwise go by the GVWR. So make it 9,900, or in round numbers 10,000. When you choose heavy options of CrewCab body, 4x4 drivetrain, and diesel engine, that doesn't leave much payload for hauling something else.

You cannot haul much of a slide-in camper without overloading your SRW. So consider only the light-weight campers such as the 4Wheel. Four Wheel Campers

At most, an 8' solid-wall camper with no slides, then travel without water in the holding tanks. And unmount the camper before you tie onto a trailer with more than a few pounds of hitch weight.

I know my OEM tires had a rating of 3,415 lb vs. my current tires’ 3,750 lb rating. If needed for squat, can I increase my weight capacity by adding air bags, or am I SOL with my single rear wheel axles as the weak link?

Look for the weakest link, not the strongest. It sounds like you're trying to rationalize overloading because your tires won't be overloaded.

If you really want to haul a slide-in camper and tow a 6,000-pound trailer at the same time, you don't have the right truck. Even the 2004 F-350 DRW wouldn't be enough truck. The 2005-up F-350 DRW PSD pickup has a max GVWR of 13,000 pounds, with a net payload of around 4,500 pounds. Even that's not enough for the big 11.5' slide-ins with one or two slides and dragging a trailer. That's why they now make the F-450 pickup, which can haul your 4,500-pound camper and 6,000-pound trailer at the same time - without being overloaded.

If you want to keep your current pickup, then instead of a slide-in camper/open trailer combo, consider a trailer that has both living quarters and a "garage" for the toy. Most of the normal "toy hauler" RVs don't have enough weight capacity to haul the Bronco, so consider a "race trailer with LQ". A gooseneck race trailer with LQ (living quarters) would probably overload your SRW too, so consider a tag. Race trailers come in all sizes, with various levels of LQ, from plain and simple to luxurous. A 16' garage for the Broncho plus another 12' or so minimum LQ would be a minimum of 28' race trailer. But if your sweetheart demands more rattling around room, they make race trailers a lot longer than 28'. Click on the following link, then on the LQ option. Also click on "tag specs" to see the various sizes of LQ race trailers they make. Pace American - Shadow GT Racing Trailers

[bugman]

Not that you are going to be legal but if you find just an 8' cab over so that it doesn't stick over the bumper your truck should handle it even with you Bronco in tow. I live on the primary route to Moab and you would not believe what I see people towing down I-70 here in Colorado and most of them are overweight. Some are doing it right but not many. It all depends on how safe you feel once the Bronco is on the trailer and you are headed down the road.

Jim

[SupaChop]

I appreciate the feedback. I don't want to do anything that is considered unsafe, especially with my family in the rig and my respect for other motorists.

I've considered the tag trailer option, but storage concerns and the fact that I would be using the camper alone most of the time and occasionally tow the bronco to the desert from coast have led me to explore different options.

I think I’m leaning towards a light slide in that sits flush with the back of my rig so I can use my factory hitch. Then I’m thinking of dingy towing my Bronco (with proper brake equipment of course), this way I wouldn’t be placing too much weight on my axles. This way I can stay under my 20k lb gross limit.

I agree the weakest link is where I should look. I think that is up to debate, because there are many variables involved. I would say from a static standpoint, tires are probably the weakest link. Depending on driving style, it could become the brakes, transmission, and the list goes on. I’ve known people who drive aggressively empty and go through brakes faster than people who haul at respectable speeds.

An F450 would be nice, but I think that would be impossible to pull off at this time. I need to find a way to keep my pre-family hobbies going with my current equipment, slightly modified as needed.

[redtopman]

My 2002 Towing guide is a litttle strange but ok I guess.

For my 2002 Crew cab with 2wd my max cargo is 1475 but if you look at the writeup with the chart it states that it allows for a 150 lb passenger at each seat. Since I have 6 sets of seat belts I would assume that the actual capacity would be 900 lbs more if you consider an empty truck. No mention of fuel.

So bottom line I thing the charts are made around the GVWR and CGWR but they can't cover every situation. The chart also says do not violate your GVWR on your fully loaded truck. No mention of axle ratings

Another confusion factor is the 5th wheel towing table. It states I can tow 13200 but a balanced fifth wheel will have a pin wt of 3000 lbs, more than my capacity for payload. Chart is misleading.

Therefore go by GVWR and GCWR for your situation.

First thing go weigh your truck with passengers, fuel and equipment. Subtract the wt from your GVWR to get your towing payload. Then do the rest of the math

[kmwharley]

I would look at your axle ratings and get your truck weighed. You can legally plate a truck for more than what the mfg states, you just cannot exceed the axle ratings. Exapmle: if you have a 4500 lb front axle, 8500 lb rear alxe and a 9900lb gvw. add the 4500 and 8500 together for 13k, it is over the gvw.....well if you register it for 13k then you can legally load to the axle limits making sure your tires are also able to hold the load. The only thing I would be careful of is the braking issue. Make sure you can slow that down and you should be fine.

[SmokeyWren]

Originally Posted by redtopman

Another confusion factor is the 5th wheel towing table. It states I can tow 13200 but a balanced fifth wheel will have a pin wt of 3000 lbs, more than my capacity for payload. Chart is misleading.

Ford assumes your wet and loaded tow vehicle weighs 6,800 pounds. (13,200 + 6,800 = 20k GCWR)

So that leaves you up to 2,000 pounds for hitch weight. (6,800 tow vehicle weight + 2,000 pounds hitch weight = 8,800 pounds GVWR.)

2,000 divided by 13,200 = 15 percent.

So all you have to do is find a 5er that grosses 13,200 pounds with 15 percent hitch weight, then be sure your wet and loaded tow vehicle doesn't weigh more than 6,800 pounds before you tie onto the trailer.

Of course, your wet and loaded tow vehicle is going to weigh a lot more than 6,800, with spray-in bedliner, toolbox full of tools and extra fluids, 5er hitch installed, floor jack and maybe a big bottle jack, cooler full of cool, Sweetheart and the kiddos and the pet(s) in the cab. Mine weighs almost 8,000 pounds without any kiddos, and the
puppydog is an itty bitty Pomeranian.

And most 5ers that gross over 10,000 pounds have a hitch weight of 17 to 20 percent of gross trailer weight when properly loaded and balanced.

The chart clearly says "max" trailer weight, but almost everybody assumes that means "normally loaded tow vehicle with normal options" and " usual percentage of hitch weight". But instead it means "absolutely no options on the tow vehicle with base trim level (XL with no AC if it's a Ford), and absolutely nothing in the tow vehicle but one skinny driver", and "a rare trailer with lower than normal percentage of hitch weight".

So yes, chart is misleading. Extremely so. But it's the same misleading numbers as similar charts published by GM and Dodge. Even Trailer Life no longer warns about the misleading "tow ratings". They even repeat this nonsense in their own tow ratings brochure. So I no longer subscribe to Trailer Life.

And yes, I'm one of those ignorant consumers that didn't figure all this out before I bought my 5er. With a "tow rating" of over 13,000 pounds, then surely I'll be fine and dandy with a 5er with a max weight of only 8,000 pounds. Right? Wrong!

CAT scale ticket on a long trip from Texas to New York:
4,440 front axle
5,180 rear axle
--------
9,620 GVW
6,340 trailer axles
------------
15,960 GCW
========

So way below the GCWR of 20k, but 820 pounds overloaded over the GVWR of my F-250 diesel-powered towing machine. And my F-250 is a 4x2, so most "normal" F-250 PSDs with 4x4 drivetrain are going to be even more overloaded.

[redtopman]

My last fully loaded scale reading on my 97 was

Front Truck Axle 3520
Rear Truck Axle 4980

Trailer axles 7960

Total 16400

So my GVW is 8500 without my wife who was in the truck stop at the time.

I expect to be a little over with my 2002 and I will weigh it first time out.

Montana manual states that their pins run 20-25 % but they have at least one model that comes in at 18 percent.

[u2slow]

Ford derates the axles on SRW rigs to match the exact payload of the factory tires.

IMO, the DRW axle rating is the 'real' rating - just make sure your wheels and tires are up to the task.

BTW, before anybody pipes up with the D80 vs. 10.5"... the 5.4L gas DRW uses a 10.5" with no GAWR penalty.

[SmokeyWren]

Originally Posted by u2slow

Ford derates the axles on SRW rigs to match the exact payload of the factory tires.

No, you've got it backwards.

Ford determines the GAWR needed for that truck, then sends out requests for bids on tires and axles that will meet the requirements. Granted, when deternining the GAWR, the engineers know the weight capacity of various sizes and load range of tires, so they specify a GAWR that can be met with available tires and still meet their design specs.

The axle manufacturers sell Ford an axle that will meet the specs without costing more than the absolute minimum. The Visteon 10.5" and the Dana 80 both are produced in several weight capacities at different cost. Visteon 10.5" and Dana 80 are designs, not specs.

For the 10.5", Visteon produces an axle that will meet the GAWR requirements of the Ford specs. If you believe the 10.5" axle rated 8,450 pounds in an '04 dually gasser is the same specs as the 10.5" axle rated 6,830 pounds in an '04 SRW, you don't understand cost control in the world of manufacturing.

When Visteon plans a run of hundreds of thousands of axles to meet a spec, you can bet they are going to engineer every penny of unnecessary cost out of that axle.

For example, the Visteon 10.5" axle in a 2006 F-250 is rated 6,200 pounds. If you bet it's the same axle as the Visteon 10.5" rated at 7,280 pounds in an F-350 SRW, you'd lose the bet. The axle shaft in the F-250 has 1.50" major diameter and 35 splines. But the axle shaft in the F-350 SRW has 1.57" major diameter and 37 splines.

Does it sound like Ford simply downrated the axle in the Ff-250? Of course not. Visteon engineers determined they could build the axle to meet the F-250 specs cheaper than they could build the one required to meet the F-350 SRW specs. So they did. The result is two different axles, even though both are 2006 10.5" rear axles manufactured by Visteon in the old "Sterling" axle plant that used to be owned and operated by Ford.

And Dana is no different. The Dana 80 comes in several different weight capacities that cost different amounts. Dana will sell the truck manufacturer the one that will meet the design specs at the lowest cost to Dana.

[u2slow]

Great theory... now for practice.

We all know the earlier 99+ F250 and F350 SRW are the same animal except for the door sticker GVWR. Ford didn't save the costs there and build two unique trucks with different ratings.

For any manufacturing process, there is a balance between saving material and mass production.

The fact that you can get a given axle (i.e. 10.5", Dana 60, Dana 80) is various capacities also indicates that its factors beyond the ring gear size that determine the rating. Conversely, when two F350 DRWs have different pumpkins, but the same outers and get the same rating, it means the ring gear size really has no bearing on the weight rating - we can also see this on completely undriven trailer axles.

My service van is an E350 cutaway. It happens to be manufactured as a SRW - yet uses an identical D70 rear end as its DRW counterpart. (width, brakes, hubs, etc). Except for a 6084# rating instead of 8000#.

BTW: This is the first I have heard of 37-splines in a Ford 10.5". I'd like more info on that if you have it.

[bosspsd]

Originally Posted by SupaChop

I think I’m leaning towards a light slide in that sits flush with the back of my rig so I can use my factory hitch. Then I’m thinking of dingy towing my Bronco (with proper brake equipment of course), this way I wouldn’t be placing too much weight on my axles. This way I can stay under my 20k lb gross limit.

Or look at an all aluminum trailer for the bronco, otherwise your plan sounds pretty solid to me. A long enough trailer will let you adjust the the tounge weight too.

[SmokeyWren]

Originally Posted by u2slow

BTW: This is the first I have heard of 37-splines in a Ford 10.5". I'd like more info on that if you have it.

I don't have more info, other than the source where I found it: 2005, 2006 and 2007 issues of the Ford Truck Source Book. My dealer loans me a copy of the "old" one each model year after he receives the new version. So when they receive their 2009 version, then I'll have a 2008 to use as a reference in responding to questions on TheDieselStop. I now have one copy of every one since the '97 model year.

That's the specs book used by dealers, Truck Department managers, fleet managers and maybe a few of the top senior salesmen to show the specs to customers. And to "get smart" about the specs themselves to aid them in selling trucks. I'm sure the fleet manager in any bigger Ford store can dig up more details, but as a minimum they should be able to show you the axle specs in the Source book.

Of course you could also remove a rear axle shaft from a 2005-up F-350 SRW and count the splines.