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Class C 4x4 Converstion

welndmn

Well Done Man
Joined
May 21, 2020
Member Number
1008
Messages
671
Loc
Concord, CA
I am starting to document this here, mainly to make sure I remember everything and see if others have some good ideas too as these is not much DIY 4x4 motorhome conversions out there it seems.
Starting off with a 2017 (Based off 2016) Four Winds 28z, Ford E450.
Plan is to run 295/70/R17 up front, and a 255/85/R16 in the rear.
Why the difference tires? The front axle needs 17's to clear the brakes, and the rear wheels are not sold in the 4.88 bore size for the RV in 17's, I'd have to machine them. The front will also be a SRW front end, I just like the look better.
If I need a spare, I can always run a spare on the front axle backwards.
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Starting to collect parts over the last few months, I got a 2016 F350 Dana 60. If you did not know the Super duty brakes grew from a 13.657 Inch rotor to a 14.291 in 2013 and newer. The stock Van/E450 is only 13.58.
Bigger brakes always a plus.
Full loaded axle, 3.55 gear, radius arms, steering, trac bar, drag link, sway bar brake lines and ABS wires $1200.
I have to round here, but stock Van swaybar was 20 mm thick, the F350 is 28mm, so thicker is better.
I plan to try and use as much ford parts as I can, but I will probally make my own track bar as the F350 has stupid ball joint lower I don't like.
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Transfer case found, 2012 F250 Borg Warner 1128F Manual shift with flange yokes, this matches the 43 spline (good god!) output of the 6r140 (6 speed Torque shift Transmission).
$400

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Step one, get rid of the dumb metric bolt pattern to match the rear axle.
I used a Motobuilt drill guide ($15) and steeping up to a 39/64 drill bit. The hubs are soft and drill easy.
Dorman 610-347 wheel stud
9/16-18 Serrated Wheel Stud - .625 In. Knurl, 2-29/32 In. Length
Uses my current lug nuts and matches the rear studs too.

Application
FORDF SUPER DUTY1988-1997

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Rear lift, I got some used F450 springs I will take apart and make an add a leaf for my motorhome. The motorhome is undersprung as is, so adding more spring seems nice, but I might have to add a lift block to it as well, no idea yet.
Probally going to start with 3 springs from below the clamp and see where that gets me.
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Building it all or using a Ujoint Offroad kit?
 
How are you going to strengthen the RV body? Those things are mostly made out of plywood, 2x4's and angle iron. I have cracked body mount supports in my Class A driving down a washboard road. If you don't, you are going to twist that thing apart.
 
I support this. Of course, like others, I'm expecting this bugger to pop and crack all over without the proper reinforcements. Particularly that slider. Beef it all up.
 
U joint only does Leaf springs, I'm keeping the coil springs. It seems easy to me, a radius arm mount (the frames are only 3" different in width), and a track bar mount.
The coil mounts are something like 1" narrow on the van vs a truck, so they almost bolt in, leafs seem harder to me.

I was going to add a few more cross memebers to the frame to help it, but other than that I'm not sure if it needs more, I have no idea, I've never done this before :)
It's not a rock crawler, it needs to get on the beach and the snow.
 
I was going to add a few more cross memebers to the frame to help it, but other than that I'm not sure if it needs more, I have no idea, I've never done this before :)
It's not a rock crawler, it needs to get on the beach and the snow.

Dig it. Sounds a bit like a smaller version of my bus. Needs traction up front so it isn't just your ass end trying to push a front that wants to bury itself in turns.
Are these built as gasketed between the camper and cab, or permanent attachment between the two? Some crossmembers in the truck chassis oughta do plenty to cut down on twisting if you're just in sand and snow.
 
Dig it. Sounds a bit like a smaller version of my bus. Needs traction up front so it isn't just your ass end trying to push a front that wants to bury itself in turns.
Are these built as gasketed between the camper and cab, or permanent attachment between the two? Some crossmembers in the truck chassis oughta do plenty to cut down on twisting if you're just in sand and snow.

I don't know about the newer ones but my 1976 has a gasket like a sleeper on a truck does
 
If there is enough room for flex in that gasket, I'd go with a 3 point mounting system to keep from twisting up the cabin.
 
I think on the newer class C's its just a seal all around the cab to RV body and they are mounted separately to the frame.
 
You will need to regear that front. I think that the e450 is geared 4.56 from the factory.
Looking forward to watching your build.
 
I am not an expert on motorhome building, but the Van part looks like it's just wood//glue/screws that attach it to the "home" part, I honestly don't see a big issue, maybe I'm wrong but I don't see a lot of information on the internet about people having issues.

Yes, I have 4.56 gears, well the UPS guy does...

I picked up some shifters, one from a fullsize bronco, the other from 2005 F-250 (the one of the bottom) to get me options to see what one fits better. ($30 each)
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I also found this little light on ebay for $5, I think a light just gives it a little more factory like look.
Still waiting on $ to buy wheels and tires before I start making this thing a giant plug in my side yard. The fun is real as I will have to work in the uneven gravel on this thing.
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You will need to regear that front. I think that the e450 is geared 4.56 from the factory.
Looking forward to watching your build.


I just found out that all RV's with the 6 speed got 4.56 gears, not other options are out there.


For fun I got a copy of the window sticker for the van part.
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I just found out that all RV's with the 6 speed got 4.56 gears, not other options are out there.


For fun I got a copy of the window sticker for the van part.

We work on these vans occationally here. I always chuckle when I glance under a newer one and see that they still haven't updated the front suspension. The van market is so fleet driven that they haven't had to make any real changes to them for 30 years. Even the power trains seem to lag 4-5 years behind the trucks.
 
We work on these vans occationally here. I always chuckle when I glance under a newer one and see that they still haven't updated the front suspension. The van market is so fleet driven that they haven't had to make any real changes to them for 30 years. Even the power trains seem to lag 4-5 years behind the trucks.

:shaking:

God forbid the OEMs have one class of vehicle on which they don't fix what isn't broke. I swear something about beam axles just brings all the morons out of the wood work.

Chevy builds a van that rides and handles like a car and kills front suspension parts like a car when you work it like a van.

Ford builds a van that rides and handles like a van but can take abuse without needing a front end fairly regularly.

If you want to feed dainty little suspension parts to something that has a blue oval on the grill then buy a Transit. They make them in cab + chassis now too.
 
We work on these vans occationally here. I always chuckle when I glance under a newer one and see that they still haven't updated the front suspension. The van market is so fleet driven that they haven't had to make any real changes to them for 30 years. Even the power trains seem to lag 4-5 years behind the trucks.


Big time, I think the Vans did not get the torque shift 6 speed until 2016, when did it come out, 2005 ish?
 
I'm hoping for some shots of the underside as you swap everything in. A bit of a lift needed to fit all the 4wd stuff without clearance problems makes me curious what it all looks like under there. As in, the shape of the underside of the "home" section and how closely it fits up to the chassis. Guessing it's just as flat as the every other side of a fiberglass RV, but I've never slipped under one to see.
 
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I am not an expert on motorhome building, but the Van part looks like it's just wood//glue/screws that attach it to the "home" part, I honestly don't see a big issue, maybe I'm wrong but I don't see a lot of information on the internet about people having issues.

Yes, I have 4.56 gears, well the UPS guy does...

I picked up some shifters, one from a fullsize bronco, the other from 2005 F-250 (the one of the bottom) to get me options to see what one fits better. ($30 each)
filedata/fetch?id=92955&d=1596641008

I also found this little light on ebay for $5, I think a light just gives it a little more factory like look.
Still waiting on $ to buy wheels and tires before I start making this thing a giant plug in my side yard. The fun is real as I will have to work in the uneven gravel on this thing.

If you've got a link for that light, I'd probably pick one up.

FWIW, I converted a Chevy van to 4wd, used the guts from a truck t case shifter, but had to make my own "box" to fit under the flat floor vs the side of the truck tranny tunnel. I used the trim piece from the adjustable slider for the shoulder belt from a piece of heavy equipment, worked really well, I'll try to find a pic
 
Camping last weekend, all my friends made fun of me for wanting to keep the stock van 16" wheels in the back, so I'm now looking for some 2003-2017(?) Dodge DRW wheels (the "Wheels" seems repetitive...) Then I will have a friend bore them out to fit over the Van hub. I'll still run the SRW front end, I just like the look. This let me look at 285/70/17 tires too, they are cheaper then then the 295's and 255's I was looking at. I'm worried the 285' might touch on the DRW axle, so it might need a 1/4" spacer too.
 
Some track bar stuff, The stock ford used a ball joint on the axle end of the track bar, most fords also seem to have some wobble as dual steering stabilizers seem to be really popular on all the forms to fix that wobble, I blame the track bar ball joint as we all know TJ's with a ball joint on the track bar also wobble.

I pressed out the ball joint, what a PITA!
You have to cut the stud off the ball joint for the ball joint press to fit over it, even then it still took heat and the air hammer to knock it out.
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The ID was 2.08 or something, so some left over 2" 1/4 tube fit pretty well inside the old ball joint hole. I added a few beads to the OD of the 2" tube so it then became a press fit for the ball joint hole.

I made 2 sandwich plates to sit on the old track back mount, I welded the 2" tube to them and added a center bolt as well to it (really overkill here, but why not)
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I have these 2 tabs in the box, they are massive so that's why I never put them on a rig, but being 3/8" plate seem to fit for an RV just fine. Bonus they are even drill 3/4 for the heim I want to use for the track bar.
Clearly, the tabs are not welded on yet as I need to know the actual height everything needs to be first.
Yes, the Tabs on the picture are upside down. they go on the other side, but that would require me to roll that axle over again for a picture and it's not worth it.
The track bar mout will be on the top side of the mount, not the underside like OEM ford.

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If you've got a link for that light, I'd probably pick one up.

FWIW, I converted a Chevy van to 4wd, used the guts from a truck t case shifter, but had to make my own "box" to fit under the flat floor vs the side of the truck tranny tunnel. I used the trim piece from the adjustable slider for the shoulder belt from a piece of heavy equipment, worked really well, I'll try to find a pic

I will e-mail the seller to find out if he has more, I don't see any others right now either on e-bay.
What do you mean "box" the shiftier boot/bezel? I just planned on finding some universal shifter boot and mounting it to the floor.
 
I will e-mail the seller to find out if he has more, I don't see any others right now either on e-bay.
What do you mean "box" the shiftier boot/bezel? I just planned on finding some universal shifter boot and mounting it to the floor.

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disregard the nasty carpet, it was swapped with vinyl at the end of the build

that's the bezel that goes over the shoulder belt height adjuster on a piece of equipment, it had a nice texture and the grey was a good fit inn my grey int 06 van, the length of the slit, and the brushes inside were very comparable to the floor shifter of my similar year gm truck

I wanted a modern looking shifter, I felt I could do better than a $13 pep boys boot
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I don't have pics of my "box" :flipoff2:but basically, you need to decide where to put your fulcrum, the floor is well above the tranny in a van, you want the linkage pretty close to horizontal to work properly, a truck typically has the shifter dog leg thru the side of the tranny tunnel with a single shear bolt for fulcrum

I built a box with tabs to bolt under the floor, shifter dropped into it, with the dog leg outside the box

Geometry was good, hit the detents with correct effort, lever travel felt natural, linkage was horizontal and didn't bind

box wasn't water tight, not real important here, wasn't meant to be, made sure it had a drain hole

I also looked at jb shifters, and liked them, vendor here

https://irate4x4.com/vendors/market...rication-llc-transfer-case-shifting-solutions
 
Camping last weekend, all my friends made fun of me for wanting to keep the stock van 16" wheels in the back, so I'm now looking for some 2003-2017(?) Dodge DRW wheels (the "Wheels" seems repetitive...) Then I will have a friend bore them out to fit over the Van hub. I'll still run the SRW front end, I just like the look. This let me look at 285/70/17 tires too, they are cheaper then then the 295's and 255's I was looking at. I'm worried the 285' might touch on the DRW axle, so it might need a 1/4" spacer too.

i ran the 255 80 17 on my dually...on factory alum rims, no spacers needed and i could run them at 65psi when towing heavy without spacers. they filled the wheel well nicely and drop my 4.10 gears a few hundred rpm...
 

Nothing worth taking a pic of. I started on some radius arm brackets, didn't finish. These are based off some I saw on the internet, so who knows if I like them.
the gears for the axle come some time this week.
I'm part of the heat wave area, it's 103-108 when I get home and my shop gets full sun, so I hang out in the pool :)
 
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