All adds you see ford says they beefed up the axles on the 2017. What does that really mean ? Stronger complete axle or just better parts inside. My 2011 350 SD has a 10 bolt custom cover will it be the same?

 

Axles are well covered here. For 2017, most models received completely new axles.

All gas trucks, except maybe the 350 dually, keep the exact same Sterling 10.5 axle as before.

Base F250 diesels keep the Sterling 10.5 as well.

F250 diesels with the HD tow package and all diesel single wheel F350 trucks get a new Dana M275 axle.

F350 dually diesel trucks get a new Dana M300 axle.

F450 trucks get an uprated version of the new Dana M300.

All of the "new" Dana axles have larger axle tubes, larger spline diameters and more splines, and larger ring gears.

 

The F450 I ordered, as near as I can tell, gets basically the same axle.
2016 --> 2017
Dana S111 --> Dana M300
Ring gear: 11.8" --> 11.8"
Axle size minor: 1.72" --> 1.72"
Axle size major: 1.85" --> 1.85"
Max rating @ ground 12,000# --> 12,000#
Tube diameter: 4.25"x4.25" --> 4.25"x4.25"
Splines: 34 --> 34

Either axle is more than big enough though.

Sources:
2017: https://www.fleet.ford.com/truckbbas...bs_-_Specs.pdf
2016: https://www.fleet.ford.com/truckbbas...SB_Updates.pdf

With the specs on the axles being identical, I'm suspicious that the 2017 specs may not be correct. Tube diameter of 4.25"x4.25" makes sense for the S111 square tubes, but not for the M300 round tubes.

Visually, the s111 looks a lot bigger.

 

The S111 may very well be bigger. A circle with a diameter of 4.25" will fit inside a square that is 4.25" x 4.25".

However, that doesn't mean it's stronger. Circles/radii/arches are the strongest designs. Designs with flat spots and hard corners are inherently weaker, because they can't distribute a point load as evenly.

It's perfectly feasible that the new circular axle tubes are stronger than previous designs, and that's before factoring in variations in wall thickness or metallurgy.

 

The news ones are cheaper, that's why they are on the truck. The design of the S111 is stronger with its third member.

 

Actually, the 2015 and 2016 F450 got the Dana S130. It was a monster square tube unit rated at 16k GAWR and 40k GCWR. Ford's documentation on it having the S110 has been wrong for a couple of years. Surprised? LOL...

Specs are on the second line of this chart.

 

Citation?

Certainly manufacturers always want to pay less for the components they put in their products, but wholesale cost isn't the only factor taken in to consideration.

 

OK, I know as muc about axles as I do brain surgery...I have the 2017 F350 4x4, DRW with 3.55 axles. If I wanted to move up to the 4.10 axle, what would it take? Or can it even be done. Not saying I want to, but if I did.

 

You'd just have to get your gears front and rear changed out, I'm not sure the typical aftermarket gear companies have gears for these rear axles yet.

 

If not, Ford has them because the 4.10's were an option on the DRW 350. So, get them, get them swapped, and update your trucks computer so it knows your new ratio. That can be done at the dealer or with Forscan...

 

So, it's not the axles what would need the changing, just the gears right?

 

Correct. Axles can come with any number of gear ratios. The axle itself is the same.

 

The pinion gear is smaller on a 4.10, so I suspect that you would either need a different carrier, or need to use a spacer on the ring gear. (I know that is the case on the GM 10 and 12 bolt rears, but I'm not sure about the Dana.)

 

Correction on my original response. The C&C specs are the same on the Ford site for the 2016 / 2017 rear (although possible wrong).

The F350 SRW & DRW did get a larger ring gear, axle tubes, and axles 2017. The brakes are also larger on the 2017 trucks. Ford doesn't have the specs for the 2016 F450 rear axle on their site - the columns aren't filled out.

Again, I'm sure the rear is more than strong enough for anything I'll every throw at it.

 

The brakes are carryover for the 2017 models except the 450. They are 14.29" vented rotors with dual piston sliding calipers front and rear. The 450 has bigger discs courtesy of the 19.5" rims. The other trucks are limited because they simply cannot fit a bigger disc into a 17" wheel.

The 350 dually and 450 share an axle for 2017. However, the 450 has larger diameter half shafts and a larger ring gear.