Decision Time - Single Rear Tires vs Dual on Ambulance

[iggi]

So I'm at a decision point I wasn't expecting and have a short time frame to make up my mind. So.... hoping for some help here.

I have a 2009 Crestline New Era. (pic below). After much internal debate I decided to go ahead on a 4x4 conversion and the next day I had a really good deal on a full donor vehicle drop into my lap. An entire 2006 F350 4x4 (single rear wheels) with relatively low km for $500. It's essentially perfect to go with the ExpoVan's conversion hit.

Now here's where I'm stuck:

Do I convert the F350's Dana 60 front axle to dually hubs and the econoline bolt pattern and stick with the duallies. (Will the stock 16" rims even fit over the F350 brakes?)
Or do I swap out my dually Dana 70 for the single rear axle that's on the truck and switch to singles?

Why is this time sensitive? Well, I have the ambo booked into the local 4x4 shop to rebuild or replace my non-functioning limited slip differential. If I'm going to swap out the rear axle then there's no point in spending money to fix it.

If you lived in Alberta, did a lot of driving in the winter, and made several long trips down the US Southwest each year what would you do?

Weight: I'm currently 9500 lbs. Once the camper is finished I'll likely be between 10,000 and 10,500 fully loaded.
Height: I've raised the roof so I'm 10ft tall. Live in Alberta next to one of the windiest highways around where semi-trucks frequently get blown over.

Ujoint recommends sticking with duallys for his motorhome conversions over going to a super single conversion. I think that's pretty valuable input.
At the same time there's a scad of Sportsmobile conversions topping 11,000 lbs that are on singles.



The kind of trouble I get myself into:



Current picture with the roof raise:


Thanks in advance for your thoughts!

 

[turbodiesel]

The minimum rim size is 17" on a 2006 F series axle. At least from the factory.

Being very close to a completed an mgkit conversion myself, I would say doing the rear is significantly more work. If you can keep the rear, it'll save you time. Also makes sure the gear ratios are the same front/rear of you keep the rear.

 

[iggi]

Thanks! Much appreciate the input. Total amount of work is a factor as well. Going to be kinda squeezed for time.

The minimum rim size is 17" on a 2006 F series axle. At least from the factory.

Bring very close to a completed an mgkit conversion myself, I would say doing the rear is significantly more work. If you can keep the rear, it'll save you time. Also makes sure the gear ratios are the same front/rear of you keep the rear.

 

[turbodiesel]

Thanks! Much appreciate the input. Total amount of work is a factor as well. Going to be kinda squeezed for time.

Welcome and good luck with the build! Love how you did the roof lift.

 

[Raul]

F350 bolt pattern will give you more flexibility to find wheels. Just make sure the load rating on the tires are OK for your weight. Fitting the rear axle from a truck will require welding new spring perches and shock mountings. You got a great deal on the donor. If I were to do it again I'll shop for a 2014 (I think) or newer with e-locker. You can get them for $1000. Installing a locker on your Dana70 will cost you more.
I have zero experience with duallies, but It seems that they have some disadvantages off-road as picking up rocks, different front and rear track and I've been in some places where they do not allow duallies.

 

[iggi]

Thanks!

I have the Dana Trac Lok in the D70, which is likely enough for the kind of places I go. Apparently the Sterling rear from the F350 has a limited slip as well so that doesn't help the decision.
Certainly cheaper and faster to convert if I stick with the duallies. Given the size of the rig and the contents of it, I think that's more the limiting factor than the DRW.

Super Singles look cool but I'm just not dropping that kind of cash on new rims & tires.

F350 bolt pattern will give you more flexibility to find wheels. Just make sure the load rating on the tires are OK for your weight. Fitting the rear axle from a truck will require welding new spring perches and shock mountings. You got a great deal on the donor. If I were to do it again I'll shop for a 2014 (I think) or newer with e-locker. You can get them for $1000. Installing a locker on your Dana70 will cost you more.
I have zero experience with duallies, but It seems that they have some disadvantages off-road as picking up rocks, different front and rear track and I've been in some places where they do not allow duallies.

 

[billiebob]

Odd man out here, I'd keep the duals.

Ex Albertan who worked oil field driving service trucks with duals all year, mud. ice, snow..... gumbo.... plus over a million miles driving semis and super bees from Yellowknife to Spokane, Rupert to Winnipeg. Super singles are not even popular on Interstate semis in the US. They are a trendy choice today for overlanders. No one earning a living driving in the worst conditions even considers super singles.

The "rock stuck between the duals" would be a great topic for Myth Busters. But given every logging truck, gravel truck, mining truck uses dual..... often on 5 or more axles.... without an issue..... I say this is a myth.

Duals vs Singles is all about weight distribution. Scale each axle. If they weigh the same Singles make sense. If the rear axle carries considerably more weight, the rear axle needs more rubber. Duals will work better. Call it science, engineering or common sense.

For the kind of trouble you get into invest in selectable lockers front and rear. More useful than a winch.

And chains, chains, 4WD, all locked up is as good as it gets. I even carry and use chains on my Wrangler.

 

[iggi]

Hey!

Much appreciate the feedback. Especially given your experience driving here in Alberta and Canadian winter driving.
Chains have already been a big help. Gotten me out of a few stucks, even with just a set of singles on the outside rear tires.
As cool as those big tires look I'd rather have something in a size I can change myself without needing a crane.
Nice to know you haven't seen that 'rock-stuck-between-the-duals' issue that gets kicked around so much online.

I think switching to singles would induce more anxiety for me than sticking to what I already know.
The duals haven't been an issue yet off pavement really. My only problems have been a combo of a worn limited slip and dropping a back wheel into a ditch or something and not having any front axle power to pull me out.
I've been totally happy with how they handle and the overall stability of the rig. I'd really be kicking myself if I spent a bunch of time and money to swap the rear axle and then not be happy with the end result. Maybe when I finally get to talk @Abitibi into a test drive I'll change my mind but at this point I think I'll stick to the DRW.

Cheers,

Odd man out here, I'd keep the duals.

Ex Albertan who worked oil field driving service trucks with duals all year, mud. ice, snow..... gumbo.... plus over a million miles driving semis and super bees from Yellowknife to Spokane, Rupert to Winnipeg. Super singles are not even popular on Interstate semis in the US. They are a trendy choice today for overlanders. No one earning a living driving in the worst conditions even considers super singles.

The "rock stuck between the duals" would be a great topic for Myth Busters. But given every logging truck, gravel truck, mining truck uses dual..... often on 5 or more axles.... without an issue..... I say this is a myth.

Duals vs Singles is all about weight distribution. Scale each axle. If they weigh the same Singles make sense. If the rear axle carries considerably more weight, the rear axle needs more rubber. Duals will work better. Call it science, engineering or common sense.

For the kind of trouble you get into invest in selectable lockers front and rear. More useful than a winch.

And chains, chains, 4WD, all locked up is as good as it gets. I even carry and use chains on my Wrangler.

View attachment 694419

 

[iggi]

Thanks, probably 5% or less based on mileage.

Unless your majority driving is muddy dirt tracks or deep snow, I suggest stick with duals.

 

[Betarocker]

Not many tires, if any, that will have the same capacity single as what a dual set provides; not even if you go up to something wide in 37" or greater diameter. Ambos have a lot of junk in the trunk ( i ).

TOYO TIRES - Europe

Toyo Tires Official Web site

www.toyotires.com

Great resource for figuring out tire pressures and capacities

 

[billiebob]

Took this video a few years ago.

This is his 4th run, the other 3 runs he made it to the light standard before spinning out and backing up onto the ferry landing wedge. You can see him almost spin out going past the light post but..... 4th time is a charm.

Tripe lockers, 4 sets of chains on the duals. 130K pounds, 460HP. 18 speeds.... I don't miss it at all.
Many reasons to love duals.... ever seen a semi blow a tire..... and keep going.

oh yeah, for the first 30 seconds...... imagine what is going thru his mind

 

[billiebob]

Besides, duals can be soo cool....

 

[billiebob]

Duals were once a factory CJ option..
after WWII Jeep was looking for markets to sell their marvelous little critter and farmers, agriculture, construction, landscape drove the design. The CJ2 was the power source for anything.









And the rear PTO drove everything from threshing machines and sawmills to concrete mixers.

 

[iggi]

That's cool. Bolt on floatation!

Reminds me of these.

You Could Buy This Wacky Two-Tire, One-Wheel Setup for Your Car in the ’80s

The narrow tires performed much better in the rain while still providing a larger contact patch for dry roads.

www.thedrive.com

Duals were once a factory CJ option..

View attachment 694456

View attachment 694459

 

[iggi]

and that reminded me of this massive hail storm I drove through a couple years back. Definitely a win for skinny duallys. Anyone with fat tires was either driving at 10kph, pulled over or was in the ditch. I barely noticed it. lol