Little late to start this thread, but I wanted to still get some opinions. Last October I started

a frame from the cab back. After a lot of searching for a replacement factory frame I gave up and used 2x6x1/4 box tubing. I have made all the cross members. It's been a long tedious project, hopefully it is worth. The only thinges I have left to do is hang the exhaust And but the bump stops on. I am debating on the bump stops? They are going to be a pain. Has anyone ever done away with them? I do haul a lot with this truck but I have never been resting on the stops or ever felt it hit them.


Here is is before paint.








After paint.

I am worried about where I spliced the 2x6 to the old frame. I've heard that the weld will break because of different kinds of steel. Has anyone had any experience with this?
any thoughts or suggestions would be nice, going to try and finish it up this weekend, but if I'm missing something I wanna get it fixed before it all back together.

 

little different will the truck bed still bolt on? and are you going to do the front half eventually?

 

I don't get why you made a tube frame

Tubing just traps dirt, moisture and salt. It will rot from the inside out and you will not know how bad it is till the frame snaps in half.

Next up.. Why did you not just get a rear section of frame and just replace yours?

YES, frame steel is designed to flex and then have a memory to flex back to it original position. The tubing will not do that

 

Do you have a picture of the frame before doing this?

 

It varies by jurisdiction, but some areas prohibit any welding on the frame. In Saskatchewan Canada, your truck would not pass a safety inspection.

 

Did you slide the new tubing inside the original frame where they meet? If so you should be good but if you just butt welded the two pieces together you'll need to weld a diamond shaped plate on the outside of the frame to reinforce that area.

Don't worry about dis-similar steel breaking… they are both mild steel and you should be OK. There are thousands of truck on the road with frames that have been modified to fit their specific application...

 

looks butt welded....but he does have a square plate on the outside...

 

Chevy's done tube frame for years and they hold up fine. The only thing I see wrong is where you mated the new to the old. I see you put a patch plate over the outside, If it were me, I'd put one inside also then I'd drill and bolt with a total of 6 bolts in a diamond pattern. The frame will never break. What you're doing is no different then what I used to do with dump trucks that had bad frames, yours is just on a smaller scale.

 

As was mentioned, if you didn't overlap the two sections then you'll need to plate over the joint. Otherwise I'd be happy with it.

The steel itself, if you used plain low carbon mild steel the it should be fine and if it were mine i wouldn't give it a second thought. People build custom vehicles with homemade steel frames all the time.

Although I would have used channel instead of box tubing. Like Brad said it can hold moisture, junk, etc.

 

Those frames are also DIPPED in a rust preventive substance. it is NOT just bare metal. Notice how the toyota frames were folding in half from not being treated?

 

It is butt welded with a plate inside and out. If it breaks I guess the front will get done as well. the tube steel is sealed up pretty good other then holes that have bolts in them so there shouldn't be to much that gets in there other than moisture. The bed fits pretty good. I only had two cross members that were not hitting the frame, I am just making spacers for them. All the lines match up good.
I searched for a frame for about a month, but everything I found would have still needed work.

 

i dunno how safe that is.id be scared to run it and haul with it for sure.if you flex it, it's probably going to be flexed and tweaked for good.i think id keep looking for a used beater truck,stove up or a rotted out cab/bed with a good frame.lots of these trucks out there are be parted out.keep looking.there's no shortage.expand your search area and be willing to travel for a 4-5 hr trip with trailer.it's worth it.be safe.

here ya go:
http://pittsburgh.craigslist.org/pts/4985669736.html

 

Where are you located in PA. I have a Fully sandblasted, painted and trussed frame I would be willing to part with

 

I'm near dubois, pa. Too far along to do something different now, but if this does not work out I'll get ahold of ya.

 

You can consider this whole deal an experiment… congrats on having the ***** to tackle this. It will be interesting to see how the fairly flexible original frame works with the stout rectangular tubing.

I stretched out a '98 Kenworth back in '00 when I built my own expediting truck. I added 7' of frame behind the original so I could add a sleeper and a 24' van body to my cab and chassis. I used a new section of frame from a Ford F700 that had been shortened to build an airport baggage loader.

During the 70's the small trucking company I worked for did a lot of frame mods to the OTR trucks we ran… we always bought older trucks and modded them to suit our operation. When we welded a frame together we always used a diamond shaped fish plate… something about the diamond shape spread the load and they never cracked. If a square plate was used we would have had cracking issues. I think that info is available on line… you may want to search for the correct answer.

Keep a close eye on things and modify as required. Good luck.