Ford F-350 axle ratings

[jpjulian]

We purchased a new Excel Winslow 31IKE last October. It has a 17,500# GVWR. Our F-250 diesel pulls it just fine but a trip to the scale yesterday shows we are 240# over our RAWR of 6100#. I can not find a dually, Ford, GM or Ram, anywhere in our area so am considering a SRW F-350. Problem is those available have axle ratios of 3.31 or 3.55. Not Ideal nor either the GVWR of 11,500#. Those of you who have a Ford F-350 SRW 2013-2014 model year, what is your rear axle rating and with what axle gear ratio?

Thanks

Joe

[Atom_Ant]

Winged One wrote:


They are building for 2015 online now. Maybe the 2014 didn't have the 4.30 available?

That could be. I'm anxious to start seeing the 2015's on the lot so I can try one out.

[BB_TX]

Not sure what your problem with the 3.55 is. I have a 3.55 on my 2012 F350 6.7 and it pulls my 35' 12,500# 5er great, even over Colorado mountain passes. On relatively flat to rolling highway it will rarely drop out of overdrive while towing.

Look at this Ford information, pages 7, 8, 9 and 10. Rear GAWR ranges from 6,290 to 7,000 for SRW depending on configuration.

[AH64ID]

Ford changed the ratios in the trans that is matched with the 6.7, there isn't even a direct anymore. With the lower trans ratios it makes a 3.55 more like a 3.73 with older trans gearing.

[Winged_One]

Atom Ant wrote:

Winged One wrote:

Atom Ant wrote:
I could only wish I had a 3.55 🙂 Even the newer DRW Ford only gets as deep as 3.73. The days of the 4.10 like mine are gone thank goodness, as I believe the higher torque of the newer engines has far overcome the gear ratio in favor of fuel mileage.

Building a f350 shows 4.30 as available on a 4x4 dually.

Oh wow - you're right. That is weird, as the specs show that the 4.30 are only available on the F350 gas, or F450 if I'm reading it right.

2014 Ford Specs

They are building for 2015 online now. Maybe the 2014 didn't have the 4.30 available?

[Atom_Ant]

Winged One wrote:

Atom Ant wrote:
I could only wish I had a 3.55 🙂 Even the newer DRW Ford only gets as deep as 3.73. The days of the 4.10 like mine are gone thank goodness, as I believe the higher torque of the newer engines has far overcome the gear ratio in favor of fuel mileage.

Building a f350 shows 4.30 as available on a 4x4 dually.

Oh wow - you're right. That is weird, as the specs show that the 4.30 are only available on the F350 gas, or F450 if I'm reading it right.

2014 Ford Specs

[Winged_One]

Atom Ant wrote:
I could only wish I had a 3.55 🙂 Even the newer DRW Ford only gets as deep as 3.73. The days of the 4.10 like mine are gone thank goodness, as I believe the higher torque of the newer engines has far overcome the gear ratio in favor of fuel mileage.

Building a f350 shows 4.30 as available on a 4x4 dually.

[Atom_Ant]

jpjulian wrote:
We purchased a new Excel Winslow 31IKE last October. It has a 17,500# GVWR. Our F-250 diesel pulls it just fine but a trip to the scale yesterday shows we are 240# over our RAWR of 6100#. I can not find a dually, Ford, GM or Ram, anywhere in our area so am considering a SRW F-350. Problem is those available have axle ratios of 3.31 or 3.55. Not Ideal nor either the GVWR of 11,500#. Those of you who have a Ford F-350 SRW 2013-2014 model year, what is your rear axle rating and with what axle gear ratio?

Thanks

Joe

I could only wish I had a 3.55 🙂 Even the newer DRW Ford only gets as deep as 3.73. The days of the 4.10 like mine are gone thank goodness, as I believe the higher torque of the newer engines has far overcome the gear ratio in favor of fuel mileage.

17,500 GVWR gives you a nice 4,600 lb payload capacity on that rig. You might be selling yourself short even with a 1-ton SRW. That pin could get heavy in a hurry over the years and a few trips to Camping World. Ours overshot the 7K RAWR on our 1-ton SRW if we tried to add any water.

[goducks10]

Cheaper to upgrade tires.

[AH64ID]

jpjulian wrote:
We purchased a new Excel Winslow 31IKE last October. It has a 17,500# GVWR. Our F-250 diesel pulls it just fine but a trip to the scale yesterday shows we are 240# over our RAWR of 6100#. I can not find a dually, Ford, GM or Ram, anywhere in our area so am considering a SRW F-350. Problem is those available have axle ratios of 3.31 or 3.55. Not Ideal nor either the GVWR of 11,500#. Those of you who have a Ford F-350 SRW 2013-2014 model year, what is your rear axle rating and with what axle gear ratio?

Thanks

Joe

Go look at your tires and see what they are rated for.

Ford uses the same axle in F-250's and SRW F-350's, rated at 9,750lbs by itself.

If you'd are comfortable ignoring the door sticker knowing that the axle itself is rated for more than the sticker then you can go off of tire load capacity. This is not uncommon, and not illegal. DOT cares about registered weight and tire capacity.

This will show you that the brakes and other important parts are the same from F-250 to F-350 SRW, just a different door sticker.

https://www.fleet.ford.com/truckBBAS/non-html/2008/vs_pdf/f250-450_08bb.pdf

[tvman44]

I would not be concerned about 240# 🙂

[ricatic]

2011 Ford f350 SRW trucks have a maximum GVW of 11500 pounds...I had one once...with a 13000 pound fiver(actually weighed at the CATS scale) hitched up, I had about 400 pounds of rear axle capacity and 200 pounds of GVW capacity left...this with a pin weight of 2400 pounds...the fiver's GVW was 14000 pounds

As you can see, it would suffice nicely for your posted weights but I have to wonder how your 17500 GVW Excel would not have more pin weight...the 3.31 or 3.55 axle ratios will not be your biggest concern with the 6.7 diesel powered Ford...When first introduced, the forums were full of speculation that these ratios would be a problem...no one in their right mind would ever consider such low ratios...the forums are basically quiet about the ratios because they have more than proven that they are fine...when the truck runs...

When you look at the availability of the 3.31 or 3.55 ratios, you will quickly see that tire size, 17,18 or 20 inch rims, determine which ratio is available...for example, the 20 inch rims are only available with the 3.55 ratio..when you do the math on actual wheel and tire diameters it shows very similar final drive numbers....

Regards

[kennethwooster]

I just traded in a F250 that had to have air bags to even began to carry my 2011 Cameo 32 ft. I agree it had plenty of power to pull the load, but not the springs. We knew we would probably buy a Lifestyle someday, and a little longer. Thus we bought a 2014 DRW, so maybe in a year or two we could upgrade to a longer trailer. Even the DRW was squatted a little but the overloaded springs were only barely touching. Congratulations on your new rig. You might need to do a search and get a dRW. It really pulled great. So far I've only pulled 120 miles but will head to Colorado in May.

[sail2liv]

How much load was in truck? Were water/sewage tanks full? w x a = m so add some weight to rear and take some from front of trailer..../I always have a load of firewood in back of truck, course nothing like a good reason to get new truck...

[KD4UPL]

The RAWR of your current truck is likely based on the tires if it's only 6,100 pounds. Upgrading to higher rated tires (and wheels if necessary) should make the existing truck capable of your trailer.

[MFL]

Joe, congrats on the really nice rig!

I have a 13 250, but have the numbers for all 13 Super Duty models.

It looks like in the diesel SRW 350 for 13, you only have the choice of 3.31, or 3.55. The DRW has the 3.73 available.

The RAWR on the SRW 350 goes up to 7,280.

The GCWR for the 3.55 is 23,500, which would be cutting it pretty close on your rig. You may need to search for a DRW 3.73, which goes to 30,500.

Jerry