Project "Autonomous" F-350


Expedition Leader
Thank you guys for all of the tips and things to check, which I will be doing over the next several weeks. Based on all this new information, I'll hold off on purchasing the Centramatics for now, and only try them as a last resort.

Meanwhile, I want to get off of this thread with my problem and move it to my build thread Here, if there are any more suggestions.

Thanks for all of the help, and Mike I'm sorry for the hijack!


Out in the Crap Industries shop this am. Here are the frame extensions I fabricated. They are 2x3 .120 wall tube and 2x2 .120 wall tubing. They will allow me to slide the box back and mount the rear winch and bumper. Originally I had an 8K winch for the rear but it was stolen from the shop. Now I have a 3K winch that will be used to lift the tailgate and other light duty jobs at the back of the truck.

These were the original plates that attached the rear bumper and back panel to the truck. I am re-using them; they will sandwich the extensions and the truck frame.

I am modifying them to work for my purposes. They have some rust pitting but are still good heavy duty parts. I got the loose rust and paint off and will treat them with some por 15 or similar product. Does anyone have any input on a good rust treatment solution? I used por15 back when I did restoration work and was happy with the results. I used it on a couple of German grey market cars that may or may not have been driven on the street. :peepwall:



Pics of these German cars or I'll unsubscribe.
Self-incrimination ******, right? LOL

Pappa, I guess I'm not quite understanding how the whole setup will work... When are you gonna get the extensions install so we can see pictures of the completed product? Also how do you have the square tubing spaced apart like that, did you insert pieces of 2" wide flat stock to use as spacers?


We have separation! I feel embarassed to post such crappy cell phone pics but my camera is broken right now. Pulled the box off the uhaul truck today. First step is to plan, of course, then get the fuel tanks mounted. I have to change the spring mounts in the rear and stretch the wheelbase so it matches the f350. I figure I will fabricate some drop down brackets and ditch the factory lift blocks. In order to do what I want, every bracket and x-member on the frame from the cab back needs to come off. It's going to be loud around here for awhile!!!!!

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Roughing out the new cross members. Have to wait until monday to get 1/2 inch flange nuts. Going to weld the flange nuts to a plate and sandwich the frame from the bottom. The flange nuts will then be captured in case I need to re-tighten the bolts. I will be able to get to the bolt heads from the top but the fuel tank will be too tight to access the nuts from the bottom unless I drop the tank. They will have a cross members on the bottom of the frame also that will create a box structure and support the fuel tank. The box subframe will have notches in it to clear the new cross members. I'm thinking about mounting bump pads to the top of the new cross members where the box will sit on it and also have my spring mounts in the same location mounted to the sides of the frame. Hope that makes sense. I will attach a new cross member before removing any of the existing ones to make sure nothing moves.



Expedition Leader
I like the angle iron side bracing. Fun welding project.

what's the plan for re-coating the frame once all the hardware / mounting work is done? Paint? POR15? Bedliner?


Tons more measuring, head scratching and changes today. I wanted to put the cassette toilet in the area behind the cab but it just won't fit there. I will have to put it in the main compartment. That means I don't have to slide the box back 32" now only 23. The storage box I want will be attached to the truck frame and standard clearance around the box will be used (2-3"). The rear axle centerline will move back 7 inches to match the f350 so I can use my JE Reel driveshafts unmodified. Since my Atlas leaf springs are 57 inches long, the spring mounts will be attached to the uhaul frame in entirely new positions. I am going to make some drop plates and ditch the factory lift blocks.

The tank is sitting on top until I can remove the factory cross members but in the position where it will locate. There is a kick in the frame that prevents it from moving any farther back.

It might not look like it, but there is enough room right here to mount my house batteries side by side along the back of the cab. They will be sunken down between the frame rails as low as possible.

The frame extensions. The rear spring mount will be located back behind where the filler hose is sticking through the frame.



Making the crossmember backing plates with captured nuts. Using flanged grade 8 locking nuts. If you are going to weld, get the nuts without plating. I had 8 plates to make so I cut four plates, then welded them together. I cut those plates in half and then measured and drilled the holes. When that was done I ground the welds off and had 4 matching plates. I welded the nuts on and am ready to drill holes in the frame using the cross member as a guide.

Also notice I labeled the plates to the side they were created on. Nothings perfect, I might need that little extra precision during assembly.



The first of the upper cross members that will also capture the large fuel tank is installed. Then I spent a couple hours grinding rivet heads off. The two factory crossmembers need to come out because the fuel tank runs the full length of this frame section. Each one has 16 rivets holding it to the frame. I got all but 4 before it was dinner time. I'll be back at it in the morning.


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