Preface - I am an engineer and informed individual. Please do not turn this into a weight police conversation and lets keep it technical and on track please.

I have a 2011 F-350 Crew Cab 172.4" WB SRW 4x4 6.7L. It has the 3.55 Electronic Locking Axle. This is not my daily driver and rarely doesn't have my camper in the back. I go offroad and spend a lot of time in the snow. I currently had Benz Springs make me some beefier rear springs and I run on a 35" 14 ply tire setup on a 19.5" Rickson steel wheel.

I am toying with the idea of creating a full expedition vehicle with it. Think Earthroamer, Global Expedition Vehicles but on a smaller scale. As you can see these types of vehicles get rid of the DRW and go with a larger single custom rear wheel setup. I have been doing a lot of research and measuring on the delta between my truck and a F350 DRW. It appears that the front axle is the same, the frame is the same and the big difference is the rear axle and rear springs. It appears the spring mounting points are the same on the frame between the two models. The rear brakes are slightly different as well as the bolt pattern (8 x 200 on DRW).

I plan on upgrading the brakes front and rear to the 2013+ 14.29" setup front and rear.

How is the bolt pattern changed from 8x170 to 8x200 on the front of a dually? Is it just the spacers or is it a different hub/stud setup?

What would it take to put a Dana 80 (same 3.55 gears) under the truck in a SRW configuration and continue using my current 19.5" wheels (8x170 bolt pattern)? I understand the width delta between my axle and running a single wheel on the Dana 80. I am not worried about that as I am going to be installing a custom aluminum flatbed and a couple inches of extra width is ok.

Do they have the Electronically Locking Differential option on the Dana 80? If not is my ECU going to be pissed?

Will my current driveline work?

Anything else I need to take into consideration?

Thank you for your time and sharing your knowledge.
Keith

 

The 10.5 is a very strong axle and I do not see a need to upgrade it. The after market however does have upgrades for the 10.5. I would spend money on upgrades before I would spend a lot of money on a Dana 80 swap.

 

My thoughts as well dually, I can't see the need for the upgrade. The axle/diff you have is very strong, very good, and provides lengthy service life.

I also am curious about your brake upgrade. Just how much of an upward move do you think you'll get by doing new brakes? The stock ones are very good. I'd bet you could get more stopping power by simply upgrading your factory pads with top end pads from oreilly auto parts. I recently installed new pads and they made a decent improvement in feel and power.

Thirdly, I'm a big fan of air bags. Installing a VIAIR #10007 air system and firestone ride rite air bags give you more load carrying capacity and better stability while driving with the bonus of having on board air for other uses.

If you're after adding some width to your axles I would think you could simply buy the same wheels you have with a different offset and gain a couple inches.

 

The only people I have seen having problems with the 10.5 not being stout enough are sled pullers running >36" aggressive tires and making more than 500 hp. Otherwise, it is a very stout unit that is rated way higher than the rest of the truck. With nothing more than 35s, I wouldn't be in a hurry to go through all the trouble of a Dana 80 swap.

How are you planning to address the vehicle speed sensor with the 80?

 

Matt,I believe drw trucks run Dana 80's, I'm thinking that's the source for the axle swap, speed sensor should be a non issue.
OP, no factory ELD was offered, you will have to look at after market options. I'm thinking the dealer could code it out if it was a problem. Far as changing the the 80's bolt pattern the easiest and cheapest solution is new wheels. To match the front you might be able to swap just the outer knuckles, but if you find a smashed donor truck just grab both axles. Might get an added bonus of lower gears.

 

Thanks guys. I guessI should have prefaced that I am looking for an axle that can support more weight. I have no doubts about the Sterling handling the power or torque but it's only rated at 7280lbs whereas the Dana 80 is rated at 9600lbs.

Yes, the stock 350 & 450 DRW trucks use the 80. They come with 3.73 ratio and available with limited slip but not EDL. The locker is available aftermarket though. I could always swap out the front gears for 3.73 if I cannot source the 3.55/3.54 that I currently have. From what I understand the Dodge axles are the same and use the same speed sensor but have not completely verified that.

The tires and wheels I currently have are rated at 5k per corner.

 

Lots of sled pullers shorten the 80's and adapt the hubs and brakes from the 10.5. Guy near Chattanooga charges $700 if you bring him an 80 and a 10.5 to do it. That way, all your hardware and wheels function properly.

 

Visteon actually rates the 10.5 at 9,750 lbs. The rating you have quoted is the rating that Ford applies and is limited by tire/wheel capacity. If you look at various F250 & F350 configurations you will see that the RAWR for the 10.5 varies by nearly 1,000 lbs. Ford can't put a rating on the axle greater than the sum of the tires and wheels.

Like I said before, the 10.5 is more than capable of what you want to do with it, but it's your time and money.

 

This should be an interesting project. I wonder if you could get your factory e-locker switch to work with an aftermarket air locker?

Getting your wheels to work is going to be the hard part. You'd need a hub for the Dana 80 axle with the correct bolt pattern, and I'm not certain they exist. UGA33 may have the best option here if you supply the donor axles.

 

I had an assumption that was the case but could not find any further information. Can you link me to something that states the Visteon is actually 9,750lbs? I could not even find the axle on their website.

Axles are rated for a specific weight "@ ground". The GVAWR is rated at the lowest component, which is usually the tires and wheels. The Ford Fleet book states the Sterling 10.5 is rated to 7,280lbs @ ground. I would really like to see some official statistics and specifications that indicate its more.


Thanks!

 

http://en.wikipedia.org/wiki/GAWR

Please help me figure out my axle specs - Ford Powerstroke Diesel Forum


There are about a dozen or more forums stating basically the same information. The only possible downside I see to using your 10.5 to carry heavier loads is the use of the ELD. That is going to be your weak point. You have 35 spline axles which shouldn't be an issue, but improper (i.e. not careful) use of the ELD under heavy loads could become an issue.

 

Far as I know Dodge is still using the AAM 9.25 front and AAM 11.5 rear. Similar in overall gear size, but not even close to Dana, and still the wrong bolt pattern, 8 on 6.5.

 

Just out of curiosity for the OP's conversion - do you have any estimated weight figures? If you are wanting to do an Earth Roamer, just smaller, I'd be curious what kind of weight you are getting in to. There are a lot of guys that run bed-mounted campers here that may be in the same ball-game, weight-wise.

Another thing to consider is the stability. With a big box of a camper-type application (more top heavy) body roll is going to be a consideration. The extra stability that is offered with a DRW (on two counts - wider track width & stiffer springs) is why a lot of people go that route. Though, customizing yours opens the doors pretty wide for the performance you want - just keep the stability in mind, not just the weight ratings.

If you move forward with it take pictures. I've been on some cool adventures with my stock truck. That would be pretty sweet to have the mods to allow bigger off-roading possibilities.

 

I currently have a Chalet Ascent S95R that I use every weekend and never leaves the bed of the truck. We (just like as I type) stay in the local resort parking lot every weekend and ski, Mt. Hood Meadows. The setup now, loaded with water, batteries, propane, gear, ect.. weighs about 4k and the truck handles it very very well. Especially with the heavier overloads, early overload engagement brackets, RS9000 shocks, huge helwig sway and air bags (35psi).

I am looking at putting in a flatbed and having a local company make me a true flatbed four season camper with the items I want in it. I have not estimated weight yet but I am guessing it will be the same if not a little lighter than what we have now.

 

So I'm guessing you're rear axle weight is somewhere around 7,700-7,900 lbs right now?