Agreed on the availability of the 4.10's just surprised even Dana doesn't list anything on the axle at all on their website... I would think at a minimum, they would list the axles specs and the gears that fit it's original release...

Also agree on the ARB comment, unfortunately since I run ARB's in 2 of my other trucks and they have been almost bulletproof under some pretty hard use... I doubt there's much of a market for people wanting to add the ARB to an M275 given its limited production use.
So is the Elec Locking Diff in the M275/M300 the Eaton E-Locker...? I've read somewhere that the ELD in those axles was designed/made by FORD... According to the Eaton website, there are no carrier breaks for the E-Locker for some of the BIG rear axles, and if that is the case, I could simply re-use the E-Locker after swapping to 4.10's and wait to see if ARB ever releases a unit for the M275... I've read a few threads about the factory ELD failing.
I might reconsider ordering an F350 and go with an F250 with the Dana Super 60 front and Ford 10.50" rear just for the fact that the gears and lockersI want are readily available...

 

There's a bit of mis-info posted earlier about the axle differences. Here's the info straight from the dimensions guide for 2017. Since the base F-250 is carry-over, there's a nice comparison to make:




In every measurement respect, the M275 is a heavier and stronger axle than the 10.5 it replaces, which was already a robust axle. I find the comparison of the 350 dually and 450 axles very interesting. Although they share the same axle tube and ring gears, the diameters of the axle half shafts as well as the spline count show the 450 has incredibly strong axle shafts.

As to the original question asked regarding u-joints and axle joints, those have nothing to do with the new rear axle(s). However, the driveshafts are new on both the front and rear of these trucks, and yes, the drive-shaft u-joints are stronger.

 

Thanks Troverman, great info. I copied and pasted it into my notes for the new F350... We certainly can't complain there's not enough "Beef" under these high capacity trucks... I've had 10.25" or 10.50" rears under 2 Super Duties and 1 Bronco (swapped in axle) and with 37's or 38's and ARB Lockers, they have been trouble free in every aspect... Can't say that for the front Dana 60's, but at least the rears are pretty much bulletproof even when modded... It's safe to assume the M275 will be even more so based on it's specs... If you get any more info on these axles, please post it here or PM me as I'm interested in knowing as much as I can on these rears...

 

One thing missing from that chart is the SRW 350 6.2 still gets the Sterling 10.5 like the F250 base. That spec chart threw me off for a while but I had to eat crow when I found it to be incomplete/inaccurate.

 

I didn't know that either. I guess that still leaves the question of the ultra-rare gas dually differential, not to mention the trailer hitch size on that same vehicle.

 

Can't help on the gasser DRW but the SRW 6.2 350 has a 2.5" hitch which also surprised me...

 

I have a SD Platinum on order with the HD tow package. I plan on upgrading wheels. Can I assume that the axle will determine which after market wheel I can choose. I talked briefly with SOTA and they tell me that they support the 12 bolt axle but not the 14 bolt. Is this the same question as is in this thread. Thanks.

 

According to and ARB rep I emailed regarding any development of an Air Locker for the M275/M300 axles, the response was that there is nothing in the works at this time... They claim they haven't been able to definitively determine which trucks get which axles and as such, have not even started any R&D nor designs for an Air Locker for these axles yet... An ARB supplier I also emailed stated it would probably be 2 - 3 years before an ARB is available for the M275/M300 axles, if and when ARB decides there is enough market for it... So for me, and I'm probably very much in the minority here, not having an ARB available for the M275 which would come under the F350 I was planning to order is a deal killer... I'll downgrade to the '17 F250 and spec it with the Ford 10.50" rear and Dana Super 60 Front so I can swap in 4.10's and ARB's in both axles... I have read more than a few stories about the E-Locker's failing to engage, or breaking under stress. My experiences with ARB's have been 98% positive and they work when I need them to...

 

So, you're worried about the factory e-locker breaking and thus you want the ARB for strength...but you're going to downgrade to the Sterling 10.5, which is weaker, in order to get it?

Makes no sense, man. Just get a truck with 3.55 gears and the factory locker. With the diesel engine, you'll have plenty of power to turn big tires. Don't forget, you still have a low range with 2.64:1 reduction. Power will never be an issue off road.

For on-road towing with big tires, consider this: the F-350 dually can be had with 3.55 gears as well. I ordered my truck this way, and in my fully loaded Lariat Ultimate 4x4 Super Crew configuration, my truck is rated to tow 27,300 lbs. Certainly you'll be towing a lot less than that which gives lots of 'spare' power to turn your big tires.

 

I would not say its a deal killer, but ARB's WHEN installed correctly are near bulletproof. I have run them F/R and love them, but not everyone does. The complaint I heard was the air lines failed....I personally never experienced a air line failure, but have been on the trail when someone did. I fixed for him and suggested he bring by my shop and I would rerun the airlines.

Every failure I encountered was due to a failure of the installer to properly attach the airlines.

TIP: Mil Spec or commercial grade UV resistant nylon ties along with regular inspections is the secret...

 

How about the front axles? The trucks I looked at the dealer had 3 different FAWR's. Forget all the exact numbers, but from low to highest rating: Standard package(~5400), Heavy front susp. package (5600lb) and snow plow prep package(~5900)

Are the axles all the same with beefed up springs, or does one get an upgraded axle?

 

All the same axle. The spring rate dictates the front GAWR.

 

X2

The Ford axles IMO are some of the best out there, well designed for strength and can take some hard use and still roll...

 

Anybody know what front axle comes with the 7,500lb fronts on heavy 450's and 550's? The build and price just says upgraded front axle. I'm guessing an upgraded 60 but really have no clue.

 

The F450 and F550 should both have the Dana Super 60 Front axle and the Dana M300 rear axles... You can look it up on the Fleet Ford site and look at the specs here... https://www.fleet.ford.com/truckbbas...bs_-_Specs.pdf