1967 CJ5 to a CJ6 Rebuild: The Road I Probably Shouldn't Have Traveled

I was thinking you were referring to a cross member strap--I saw a few CJ6 frames with this cross member straps, but thought they were added by the owner. I did not know there was added plate/strap along the length of the frame. Do you think this was to add thickness to increase rigidity/strength for the longer wheel base? Would boxing effectively accomplish the same thing or should I add the strap as well?

 

All of the above!....................Yes boxing would at least do a similar job.........and while were talking about your chassis , normally one would want to see a longer gusset / plate to bridge the cut / extension in the frame. Something around 12" either side or 24" in your case. The longer the better.
On heavy duty equipment the norm would be to install a tightly fitted channel that was bent / broke to fit the exact ID's and radius's of the inside of the frame rail.......that bridge would be at least the material thickness of the base metal or greater and extent several feet in both directions capturing any cross members that the ends would now have to be shortened. Then welded in a pattern not to add additional stress. The outside / inside crack prior to fitting the channel can be V'd out and welded up to finish...........Aluminum frames normally use the same fix with a pre-bent channel but are bolted together inside the flange........the outer and inner crack is V'd and welded but due to the heat treat in the aluminum no other welding can be done other wise failure is almost immanent. Good Luck on your project.

 

Yep, and the fishplates should not be square ended. They should come to a point in the center of the web of the channel. This helps transfer stress longitudinally down the channel.
The way that frame has been plated does not do this. It has created 2 stiff spots, one on each side of the plate, which will be prone to cracking.

 

Okay...so did I create an epic fail? Is there a way to fix what I've done?

 

Hard to really tell from here what you have...........just giving suggestions. Perhaps you have a friend or someone nearby that is qualified that would take a look at it closeup......the plate / gusset has to be able to spread out the load and stress over a longer / wider distance to be effective.........I think you may be able to work around what you have but have a qualified person near you take a look. It's just metal and can be fixed.

 

I vee welded the 45 degree butt-joint, then constructed a 3/16" thick inner bracket (upper and lower 2" plate welded to a middle plate) spanning six inches, and a 1/4" thick outer bracket that spans 8" on the opposite side of the frame rail that is constructed the same way. These are both welded to the jeep frame rail. Then, I also added grade 8 bolts just as a backup (I am an amateur welder). I think to alleviate the square end (stiff spot) on the frame (mentioned by Southtowns27), I will try to grind the weld on the web of the outer frame rail bracket and vee weld a 3" Triangular piece to both sides of the bracket, and of course weld all sides of the triangular piece to the frame rail web. Suggestions or comments?

 

Okay. After a lot of conversations and everyone's input I decided to scrap my efforts so far and build my own "stacked" frame. I have studied some other threads on this and other forums and decided to go with the plans that were used on a JP Magazine project. I will post my hand-written plans. Please tell me what you think.

 

I think you are on the right track. Refering back to your previous frame, you were on the right track when you cut the two frames on a 45* angle, but when you made your re-inforcing plates and made vertical welds you kinda through it all out the window. As mentioned, the plates need to be much longer and vertical welds on any frame should be avoided at all costs.

I would be hesitant to build a frame without having the tub available for reference. I know you are anxious to get started, but unless you have tried and true plans for a CJ6 frame you may be taking a chance that can come back to bite you.

 

I would agree with Posi above.............. It would be a good Idea having the CJ-6 body there.........especially for where the kick-ups need to be placed at either end of the new chassis. If your using your old axles , you have those spring pad dimensions , but if you ever wanted wider axles now is the time.........frame width should be well thought out for either leaf or coil suspensions along with transmission and exhaust system clearance's.
If you have not already done so get 2x4x.188 wall Rect. Tube........The .120 is probably strong enough for the the ends but since all of the brackets that you will be using will be either .188 or .250 thick it will make the welding between the two much easier.

 

I have done something similar to what you are trying to do. I found a pile of garbage cj2a/3a/3b parts for free on craigslist about 10 years ago. I am just getting to the end of my project. Yes its taken me that long. I too lengthened my cj2a pile, but only a foot in the door.

From my experience, you should have a body on hand to reference the points you need to make it all work. I made my body with the exception of the wheelhouses, cowl, dash, and all the frontend body parts. When I started the project I was a crappy welder with a crappy ac/dc buzz box. Im much better now.

What i would do is grind out your welds that go vertically down the frame and fix it. The stacked frame is a great idea, but you have zero reference points. One opinion I have is to build your new frame, but I know it will be easier to just fishplate the old one. If you have the money, buy the body either used or new and reference it continuously throughout your process.

there is a good likelihood that when you are finished, you will look at your early stuff and want to redo it. I sure do. The upshot is that with some perseverance you can take your pile and drive it out of your garage. try and make it as easy as possible. its already going to be a lot of work.

 

Update: After trial and error I discovered some errors in my plans. The worst error was that I calculated the overlap of the stacks to be only 4", when in fact they were 5 5/8". I discovered this after already cutting my material. I had to order more 2 x 4. Below are the plans I think are in their final form...hopefully.


I changed the 2" drop from my plans before because I want to be able to pull a small trailer, and I thought welding another piece inside the rear stack and then gusseting the pieces together would be a lot stronger.

 

Here are some pictures of my progress so far.


Using my school's ban saw to make more precise cuts. Good thing I get along with the Industrial Arts teacher.




I capped the ends of the stacks and center pieces first, and then put the others in place.


I cut out the rear stack with an acetylene torch, ground the slag and welded the two pieces together.




Next, I cut, ground, and fit the gusset plates for the rear pieces to weld.


This is the the finished rear stack with the 2" drop. I will add 4 grade 8 bolts just to make sure.




Getting one frame-rail lined up to be tacked into place.

 

I am building a CJ6 here in Alaska. This is my second CJ6. The original frame for this CJ6 was in pretty bad shape, the longitudinal straps on the frame rails were loose from the frame rusting away. I chose a different route, I was given a V6 Commando parts car, the body was toast but the frame was very good, I started measuring and found the Commando frame was almost identical to the CJ6 frame and was (Factory?) boxed between the front and rear spring perches. Too late for you now, and I apologize for that, but future CJ6 builders may want to consider this option. Very nice work, BTW. Good luck!

 

In my part of Ohio, Rick Riley is a guy who every early-Jeeper knows or has sought his advice at least once. I talked with him about finding a CJ6 frame, and he suggested that I find a Commando frame, like you did. The benefit of the Commando frame was that along with having nearly identical measurements to the CJ6, the spring mounts are on the outside of the frame, which he said would have a better ride. At the time, I had already sunk money into two frames that were sub-par, and decided I would start from scratch. I think the Commando frame to CJ6 is a great idea if you have a good frame like you found. Best of luck. Are you posting pics? I would love to see your progress.