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

[ricatic]

avvidclif1 wrote:
Oops

no harm...no foul..this discussion shows up about once a month...the posted Ford specification page on this thread should put this myth of different SRW axle sizes to rest...

Regards

[avvidclif1]

Oops

[ricatic]

ah64id wrote:

avvidclif1 wrote:
There's something different as the F350 shows 1080lbs more capacity. Maybe its not a misprint as larger axles could account for the difference.

Yeah the stickers are different, it's a sales thing an F-250 has to be rated less than a F-350 SRW.

People want to perceive the difference so it's put on a sticker, Dodge and GM do the same thing. Dodge and GM don't even switch axles for a DRW. A 2500 diesel has the same axle, with the same AAM weight rating, as the DRW CTD.

It's been proven time and time again how few differences actually exist.

There are differences between the F250 and F350SRW...but they are not in the axle assemblies...They are absolutely identical right down to the bearings and brake assemblies...one does not need to be an armchair engineer to be able to read parts breakdowns and determine the axle assembly part numbers are identical between the two SRW trucks...

There are two notable and noticeable differences beside the door pillar sticker...the F350SRW truck uses a two inch taller spring perch block than the F250...this taller stance increases the amount of distance the spring has to compress and stiffens the rate...secondly, the F350SRW truck has an additional spring set above the main spring pack. This spring only engages when a heavy enough load compresses the rear suspension enough to set the upper spring against the lower spring...these are the main factors in the increased capacity of the F350SRW...just the facts...

Regards

[jpjulian]

ah64id wrote:

jpjulian wrote:
I was a weight cop for the state police for a long time so am very conscious of the various weight issues.

As a weight cop what could you ticket for?

Everything I have read and heard from local cops is registered weight and tires.

With the proper tires a F-350 will have a 7180lb RAWR, for the same axle/tire rating as your F-250.

I could ticket for tire rating violations or GVWR violations. Registration also. Personally, I rarely cited non-commercial vehicles. Too little time to mess with Moms & Pops when there was such a glut of commercial vehicles to go after. Nevertheless, state regs can cause some serious grief to someone who takes a seriously overweight RV combination on the road.

[jpjulian]

jeldridge97 wrote:
Joe,

Here's the info from the door jam on our 2013 F350 Diesel 4x4 CC SRW.
Front 5600
Rear 7000
CCC 3429

The truck has Michelin LT275/65R20 tires.

Jerry

Thank you for being the one and only to answer my question.

Joe

ps..... Thanks for the other posts, but, a direct question deserves a direct answer, not some theoretical answer.

[AH64ID]

avvidclif1 wrote:
There's something different as the F350 shows 1080lbs more capacity. Maybe its not a misprint as larger axles could account for the difference.

Yeah the stickers are different, it's a sales thing an F-250 has to be rated less than a F-350 SRW.

People want to perceive the difference so it's put on a sticker, Dodge and GM do the same thing. Dodge and GM don't even switch axles for a DRW. A 2500 diesel has the same axle, with the same AAM weight rating, as the DRW CTD.

It's been proven time and time again how few differences actually exist.

[avvidclif1]

There's something different as the F350 shows 1080lbs more capacity. Maybe its not a misprint as larger axles could account for the difference.

[ricatic]

Somebody should make that post a sticky so we can direct the next poster that still believes there are different axles between the F250 and F350SRW truck...great post...

Regards

[BB_TX]

ah64id wrote:
Here is where the misprint looks to have come from. It appears to be a spacing issue as the bottom specs are for a Dana 80, and are missing from under a Dana 80.

That makes sense.

[jeldridge97]

Joe,

Here's the info from the door jam on our 2013 F350 Diesel 4x4 CC SRW.
Front 5600
Rear 7000
CCC 3429

The truck has Michelin LT275/65R20 tires.

Jerry

[AH64ID]

Here is where the misprint looks to have come from. It appears to be a spacing issue as the bottom specs are for a Dana 80, and are missing from under a Dana 80.

[8iron]

BB_TX wrote:

ah64id wrote:
.......

What if the 250/350 uses the same axle? It does, BTW.
.............

According to Ford web site:

.............................................................F250....F350 SRW
Axle Shaft — Spline Minor Dia. (in.).....1.36.......1.50
...........— Spline Major Dia. (in.)............1.50.......1.57
...........— No. of Splines (Hub End)..........35.......37

So the axles are not the same.

According to the Ford parts manual and the manufacturer (Ford/Sterling) they are the same. It is confusing but many here have confirmed it for themselves...

[AH64ID]

ricatic wrote:

BB_TX wrote:

ah64id wrote:
.......

What if the 250/350 uses the same axle? It does, BTW.
.............

According to Ford web site:

.............................................................F250....F350 SRW
Axle Shaft — Spline Minor Dia. (in.).....1.36.......1.50
...........— Spline Major Dia. (in.)............1.50.......1.57
...........— No. of Splines (Hub End)..........35.......37

So the axles are not the same.

BB...all Ford F250 and F350 SRW trucks are equipped with Sterling Axle Plant manufactured axle assemblies...These are assembled in the Sterling Heights Axle Plant nearby...and which has my BIL as the number two man in the entire building...my information comes directly from him...they are the same exact assemblies shipped to the Louisville Assembly Plant with no designation as to which of the SRW series trucks they may be mounted...

The larger axle diameter you mentioned only comes on the F350 DRW trucks which are equipped with the Dana manufactured axle assembly. This confusion continues even today because Ford has not fixed the mistake in the specification publishing...maybe some day Ford will fix the mistake...

Regards

Makes sense as we know its used on 250/350 SRW trucks.

[ricatic]

BB_TX wrote:

ah64id wrote:
.......

What if the 250/350 uses the same axle? It does, BTW.
.............

According to Ford web site:

.............................................................F250....F350 SRW
Axle Shaft — Spline Minor Dia. (in.).....1.36.......1.50
...........— Spline Major Dia. (in.)............1.50.......1.57
...........— No. of Splines (Hub End)..........35.......37

So the axles are not the same.

BB...all Ford F250 and F350 SRW trucks are equipped with Sterling Axle Plant manufactured axle assemblies...These are assembled in the Sterling Heights Axle Plant nearby...and which has my BIL as the number two man in the entire building...my information comes directly from him...they are the same exact assemblies shipped to the Louisville Assembly Plant with no designation as to which of the SRW series trucks they may be mounted...

The larger axle diameter you mentioned only comes on the F350 DRW trucks which are equipped with the Dana manufactured axle assembly. This confusion continues even today because Ford has not fixed the mistake in the specification publishing...maybe some day Ford will fix the mistake...

Regards