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jpywell52 02-02-2012 04:21 PM

Show me your frame repairs that have worked or failed!
Hey folks,

I'm about to attempt to repair the frame of my CJ. I'm a reasonably experienced amateur welder so I'm not going into this totally blind but thought I'd ask if anyone has pictures of frame repair jobs that have worked or failed epically (as one can learn almost as much from failure as from success).
I'm attaching the before photo.
The rust spot on mine is on the passenger side just above the skidplate/trans mount holes. The hole is 11" long and only effects the inside section of the boxed frame the outer section of the box is solid all the way round and in fact seems to be coated with the original paint(? or coating)

My plan is to remove the rusted metal a couple inches up and out from the existing hole so I'm welding to something solid, then do a lap joint all the way around with 3/16" plate bent to match the profile of the frame.

Comments and suggestions welcome, I'll be posting pictures as this comes along.

ejeeperguy 02-02-2012 04:46 PM

1 Attachment(s)
Rear frame was gone.Had a machine shop make me one .This was before the online catalogs sold them.It only ran me 65 bucks and some welding time.

mopar346 02-02-2012 06:39 PM

Not mine but here is a Jeep build thread on Moparts, by an absolute artist. A little more involved than yours but it's over the top.

243 02-02-2012 07:10 PM

I did not have major frame repairs but I did need to repair quite a few captured nuts that broke off inside the frame. There are several ways to make the repair but this is how I did it.

I knocked the factory nuts completely out in some cases and cut two slots across the holes and knocked the tab out. Then I used a magnet to hold the Grade 8 nut inside the frame and ran a bolt and nut down on it to hold it in place. I welded the inside nut to the frame through the slot on each side. On several holes that still had a nut in place, I drilled a hole right next to it and plug welded it.

chet44 02-02-2012 08:00 PM

I had rot in the last two inches of my rear frame rails, and the rear crossmember was mostly rot as well. I had to cut off about 5" of the frame rail ends till I got to metal I felt comfortable welding to. CAUTION!! I am lousy about in-process photos, so I apologize in advance for pic quality and the fragmentary nature of the pics. :D

So, first I fabbed new frame rail ends. I had to split some 2x3 tube, machine the two halves, weld them together, then machine the height and width to match my frame rails:

Then I welded in steel blocks, which I drilled and tapped for the shackle mounts:

Then I drilled thru holes and welded steel pipe inside for the frame tie in bolts:

So, frame rail ends done, I fabbed up reinforcing plates for each rail (top, bottom, left, and right sides of each rail):

I also made some angle brackets for frame tie-in's (one on each side of each rail. (No pics of those).

Then I clamped the new rail ends on and tacked and butt welded them on:

Then welded on the reinforcing plates:

Inside of pass. side rail:

Outside of driver side rail:

As you can see, I put the frame tie-in bolt holes too close to the end of the rail, so I only used the forward holes. I ended up welding everything in place anyway. Better safe than sorry :o:

If you are wondering about the slag and spatter, I used a 220v stick welder. I have a MIG, but it is only a 110v. Once the frame rails were complete, I fabbed a rear crossmember out of a piece of channel (3/8 x 1-1/2 x 4"). This is the only pic I have of it in process:

In that pic I have the body lifted off the frame so I could weld underneath. The bottom edge of the tub sits about 1/8" above the crossmember when I finished. I put a piece of rubber U-trim around the bottom edges of the tub to close the gap. If you want I can take some "finished" pics, but with the bumper and spare tire carrier on, you can't see much.

Overall, I rate this repair as a success (except for the bolt holes at the ends of the rails, darn it!). When I jack up the rear end I put the jack on the bumper without even thinking about it. This frame repair also beefed up the rear rails so I feel much better about the frame tie in I did for the sport bar.

CrankyD 02-03-2012 05:48 PM

This is the thread that has my frame repairs, I used a scrap piece of steel tube (2"x4" IIRC) cut the rusted section out leaving just a "strap" of the top of the existing frame. I cut the steel into a U shape the height of the inside dim. of the rear X-member then squared it all up and burned it on. I butt welded the U shape and built up a light fillet along the top. The existing frame curved down forming a nice bed for the weld.
I have been driving it since shortly after those pics were taken, wheeled it a few times and twisted it up a lot to see if it would hold. so far so good!

jpywell52 02-04-2012 02:33 PM

My plan is to remove as little of the frame as possible, probably a 1" high and 14" long, weld in new nuts for the x-member mounts then bend a section of 3/16" plate and butt weld that in. Sound reasonable?

chet44 02-04-2012 03:31 PM

The amount of rot (rust) will determine how much you will have to cut out. And unfortunately, you won't know how much to cut until you start cutting.:(

The rust holes in my frame rails were only 1-1/2" back from the end. When I cut that off, the inner wall of the rail was thinned down to less than 1/32". Cutting off 1" at a time, I ended cutting a total of almost 6" from each frame rail end til I got to 3/32" of inner wall thickness. The top, outer, and bottom sides of the rails were fine.

jpywell52 02-05-2012 08:24 AM

Good point. Ill wait to make the patch until after I do the cutting.

jpywell52 02-07-2012 03:26 PM

1 Attachment(s)
Used my angle grinder to remove rusted section. Not as bad as I had originally thought.

chet44 02-07-2012 04:59 PM


jpywell52 05-01-2012 05:16 PM

So its been a couple of months and I decided for the time being to just throw it all back together and try and drive it around. The one advantage of having cut the frame section out is i can just use a nut and a bolt to hold the crossmember in.;)

Anyway, I know its dangerous and bad and its only for around the block. Just out of curiosity how thick is the inner wall of the frame supposed to be? Mine seems uniformly thin, like less than a 1/16"

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