4x4 U-Haul conversion ideas needed

[pezfallout]

So initially I posted in the big vehicles section because I was going to get an Isuzu NPR (or similar) to build my new rolling studio apartment. After mulling it over and researching quite a bit I decided that while the initial price is right, the limited options I had with it just made me scrap the idea. Too expensive to convert to 4WD, parts not as readily available and not easy to work on alone or without well prepared shop (vehicle weight was brutal, too!)

So then I figured out my barebone priorities:

1. Had to be 4WD
2. Had to be diesel
3. Had to be able to move the box from one chassis to another easily in the event of a catastrophe. (very little external plumbing, quick disconnects for everything) If this is going to be my home it needs to be able to move as I move.

So that boiled it down to the 3/4 and 1 ton trucks from 90-98 that were in my price range. I have no personal affinity for any domestic brand trucks (I'm a Toyota fan but they don't offer a diesel in the Tundras or else that's what I'd have gone with) so it boiled down to which engine I felt more comfortable working on and hauling my life around with.

1. The 6.2/6.5L Detroit in the Chevy/GMCs had decent mileage but weren't very powerful and had iffy reliability.
2. The 7.3L PS in the Fords had good reliability and power but the mileage seemed very inconsistent and not amazing in the least.
3. The 5.9L Cummins was a very heavy power plant but seemed to have the best track record and the best mileage. Also, being an inline 6, had fewer moving parts and easier access to vital components.

Even though Dodge is synonymous with "falling apart," this is the route I'm going to go. So with the vehicle out of the way... now the living space.

I would like to get a 10' of 14' U-Haul box (preferably the 14' for the cab over for the bed area) and mount it to the rails of a W250/350 or Ram 2500/3500. The interior of the box should be rather straightforward since all of the walls are straight with no funky angles. I can raid some motorhome junkyards and piecemeal it together and save the big money for the batteries, inverter/controller, and solar panels.

I know people have converted the U-Hauls as they came (2WD, F250) but has anyone moved the entire box onto another 3/4+ ton vehicle and what did they encounter? It should be an easy swap, possibly needing some risers but it shouldn't.

As far as inverters/controllers go, can I get some reviews of what you guys are using? Looking for intelligent ones with good metrics displays with dump circuits (for excess voltage), solar inputs and if it has hookups for 20/30a service.

I'm moving back to the states in 9 months and want to have my game plan laid out. I'll have 90+ days of leave and if I can get it livable I can work on it as I go after that. I will post up other plans as make firm decisions about where I'd like to go with the build.

I really appreciate this site! So much good info. With that being said, if it's already been answered just point me there! Thanks!

 

[mog]

So that boiled it down to the 3/4 and 1 ton

I would like to get a 10' of 14' U-Haul box (preferably the 14' for the cab over for the bed area) and mount it to the rails of a W250/350 or Ram 2500/3500.

I don't know how the U-haul boxes are constructed, but my 14' Marathon box (.040 alu walls, 2.5" hardwood floor) is in the 2000 pound range. You might be starting with a pretty heavy load for a 3/4-1 ton truck right from the start ?

 

[r_w]

The uhauls are chassis cabs, the frame rails are long and straight unlike pickups. Plan on welding the frame if you buy a regular pickup.

Cab height may be an issue depending on what year you look at. You can lift the box to clear the cabover, but that messes with center of gravity.

 

[dwh]

As far as inverters/controllers go, can I get some reviews of what you guys are using? Looking for intelligent ones with good metrics displays with dump circuits (for excess voltage), solar inputs and if it has hookups for 20/30a service.

Diversion controllers - i.e., have a dump load connection - are for wind generators. You have to keep some load on a wind turbine so it doesn't freewheel and overspeed. Once the batteries are charged, the incoming power is switched to (usually) some form of resistance heater - either to heat air or water - so that there is always some sort of load on the wind generator.

Solar charge controllers don't have that feature since solar panels don't need it. When the batteries are full, the charge controller just switches off the input from the solar panels.

There are some charge controllers that can do either wind or solar, such as the new Midnite Classic. Bloody expensive unit to use for a small RV solar setup.

There are some solar charge controllers with a built-in LVD (low-voltage disconnect). These can turn on a load when the battery has enough charge, and disconnect it when the battery is low. They are generally limited to 10a load though, so if you needed to switch a larger load, you'd have to rig the LVD to operate a relay to control the bigger load.


Also, you won't find an integrated solar charge controller / inverter (for off-grid use, there are plenty available for grid-tie use). There are inverters which also have a battery charger built in, such as the Prosine, but they don't have solar charge controllers; The inverter/charger units can only charge the batteries from a generator or shore power. When there is no shore power, they are just inverters that draw from the battery and feed the AC loads. When there is shore power, they switch to battery charger to charge the batteries, and route the incoming AC out to the AC loads. (They cut the inverter out of the circuit, since it makes no sense to feed power to the battery with the charger section, and then suck it right back out with the inverter section.)


Generally, most solar rigs look like this:

solar panel(s) -> charge controller -> battery -> inverter -> AC loads

 

[Ohaul]

My current truck is a 1990 F-350 retired U-haul.
It serves me for several purposes #1 hauling sporting goods (biking:bike_rider:, scuba:snorkel:, rafting/tubing) & #2 a base camp. #3 garage space cuz we live in a small condo.:Wow1:

Here is what I have learned by living with a u-haul for the past several years.

-heavy! I don’t know if the box is 2000LBS but I would believe it. Mine is a F-350XL (F35 C&C from ford?) the way mine is loaded it sits at/on the overload springs most of the time. A F-250 sounds way too light duty to me… Its constructed from FRP, ½” ply with fiberglass on each side for a total thickness of about ¾”. I mounted closet maid shelving on the inside by drilling thru the box and bolting with ¼” SS carriage bolts.

-the mounting of the box is not the same as a service box or other parcel van box. (i.e. not U-bolts or threaded rod) it’s more like heavy angle that the floor pieces are individually screwed thru.

-yes it’s a cab & Chassis truck but mine does “hump up” at the rear axle. So there are spacers along most of the frame & little blocks at the axle hump.

-the box won’t fit a standard pick-up. Most trucks are either 6-1/2ft (ish) or 8ft (ish) beds. But U-haul is 11+ft of bed and 3+ ft of cab over. That where U-haul gets “14ft”. So to transplant you would need to get a longer Cab & Chassis (I think its 84” Cab to Axle) or stretch a frame… the longer frames are really difficult to find in crew or extended cab… but I have seen some 4x4’s

BTW mine does have a very complete electrical system. Some of the components are: Shore power plug is 120vac 15/20amp, 1500watt xantrex inverter, 2x GC 6Volt batteries, 260 (rated) watts of solar, xantrax solar controller w/meter display, Voltage sensing relay to the alternator. Outlets for 120vac & 12vdc spaced throughout the box.

-O

 

[sarconcepts]

OHAUL is right on several points, the u haul box mounts directly to the 34" frame rails, with two (each rail) 5/16" bolts, countersunk flush with the floor surface. When taking my 14' box apart, many of the bolts were frozen, plan on that, there were 14 floor boards, hence 56 bolts. How you pick the thing up is another issue, but it is done regularly, go ask at u haul, they were pretty helpful when I was box shopping. You will need a chassis,12' frame, 84" cab to axle for the 14' box, verify cab height first, because the 'E' series (the van fronts) have a higher cabover than the 'F' series (the truck front), so choose which one fits the best. The boxes are heavy, so I wouldn't go with anything lighter than a 3500 myself, this increases the brakes for the additional load. What I did to get the inside finished was carefully screw #12 countersunk screws into, but not through the 9/16" thick FRP panels (don't drill through) through 1" x1 1/2" furring strips strategically placed to then screw 1/4" ply on the interior, as well as use for cabinet & counter connections for the ledgers. Also glue these furring strips to the FRP, & they'll hold just fine.
You probably wont want the roll up door, so think about how you'll revise the rear wall.
remember, the 14' box is only 11' long, plus the 30" cabover,

 

[pezfallout]

Thank you all so much for the input, it's really a huge help to get inundated with this kind of info!

After consideration of power, I've decided to go 12v throughout the entire living space. My cooking will be handled via propane and my refrigeration will be 12v as well as the small LED/LCD media display, high efficiency AC unit, water pumps and LED cabin lighting.

Only one or two low wattage on-demand inverters will be needed for small appliance charging (cell phone, laptop, etc.)

With sufficient solar coverage and power-miser equipment I can save on purchasing shore power equipment and rely on the truck's alternator in the event of a low-power emergency. It should never reach that point with a sufficient power bank. I'm thinking 4-5 D31M Optima BlueTops which would be 300/375aH and could be abused and recharged and require no maintenance. I still need to get a baseline and what my usage would be (then doubled!) but I'm sure I that will be more than enough.

Will continue this post in a bit, leaving work!

 

[dwh]

Only one or two low wattage on-demand inverters will be needed for small appliance charging (cell phone, laptop, etc.)

I got 12v adapters for mine and now I pretty much never use my inverters. Also have a 12v - 5v to power USB.

 

[DzlToy]

A 14' FRP box is everybit of 2200-2400 pounds dry. That is a LOT of weight for a 3/4 ton or 1 ton truck, especially with the cabover and an 1500 pound driveline up front (engine, trans, t-case) I would suggest some serious design research on things like GAWR, suspension capacity, lengthening frame sections, etc. If you are using an 11' box with a 3' cabover you should be right at 2000 pounds or maybe a tiny bit under. Remember these boxes are bare bones and everything from wiring to insulation to cabinets has to go in depending on your build plans. You could see a 5-6k pound load really fast if you arent careful. That would be ok for a properly fitted truck but I would not want to drive it off highway on anything other than a wide groomed dirt road.

The truck will need upgrades to handle the size and weight, IMO but I think it can be done on a domestic pickup chassis, but remember they fall apart with heavy use, they are NOT Toyotas.

Two schools of thought are do it on the cheap and upgrade things as they wear out or build something bigger, better, custom, etc., which it sounds like you dont have the budget for. I would try a mid 90s 3500 Dodge over an early 90s (first gen body) for sure and stay with a 12 valve (mechanical) diesel engine and a manual transmission. You will need to upgrade your transmission for sure or get a manual and look at an after market clutch like South Bend or Valair.

I would stay away from Optima, though Blues are the best of the group, and consider something like a Lifeline or Odyssey. AGM is still lead acid technology (old heavy and not great for repeated charge and discharge applications) If you are going to use it however, I think there are better options that Optima.

 

[pezfallout]

I got 12v adapters for mine and now I pretty much never use my inverters. Also have a 12v - 5v to power USB.

I see what you're saying. It would be a lot simpler to just wire in an outlet for the laptop to run straight off the 12v with an aftermarket adapter. Most of them I see come with the lighter plug and I could leave it as is and install a recepticle for it (so I could plug an inverter in if necessary (visitors with electronics?) or change the plug to whatever standard I decide to run. Definitely not going to use 110v outlets; don't want anyone trying to plug into them, unwittingly. Love that tidbit, thank you!

A 14' FRP box is everybit of 2200-2400 pounds dry. That is a LOT of weight for a 3/4 ton or 1 ton truck, especially with the cabover and an 1500 pound driveline up front (engine, trans, t-case) I would suggest some serious design research on things like GAWR, suspension capacity, lengthening frame sections, etc.

I would stay away from Optima, though Blues are the best of the group, and consider something like a Lifeline or Odyssey. AGM is still lead acid technology (old heavy and not great for repeated charge and discharge applications) If you are going to use it however, I think there are better options that Optima.

To address the box weight, you're 100% correct. I'd been looking into find exact specs on it and it looks like it's going to be a little implausible. Obviously, I could build upon one of the U-Haul trucks as it comes but then I'd have to source a complete F350 4x4 front end, transmission/transfer case/drive shaft and swap it over. I've played that game before. It's not fun. Miserable is more like it.

It looks like a better option, albeit a less aesthetically pleasing one, is to purchase an aluminum flatbed (or have one made) and mount an ultralight trailer onto it. hopefully I'll be able to pick up something vintage that I can strip down and redo to my needs. An old Airstream would be sweet but a little unlikely. Without the axles/wheels they're really reasonable on weight.

As far as the batteries go, the only reason I listed the Optimas was the fact that they're AGM and can be beaten up without a lot of fuss. I know they're a lot of options, I really do need to look into more of them (and will) before shelling out a grand or more on a bank of them!

Depending on what kind of time I do have to get this accomplished (I'll have 90 days I can take off but I would really rather not burn all of that up!) it wouldn't be terribly hard to custom build a camper, but projects have a way of taking 10x's longer than they should. Even gutting an old one and rebuilding it properly will take a few weeks by myself. We'll see if I have any extra hands to help when the time comes.

There are times I wish I was 4 foot tall instead of 6'2, then I could buy one of the micro teardrop trailers and still stand up in it! Would be super easy to mount on of those.