cj-7 frame and the yj

[drag0n]

i have an 89 yj (6cyl 5spd) and i have a pretty decent crack in the drivers side framerail (i have pictures of the framerail http://drag0n.homelinux.net/jeep/ inside.jpg is the view of the inside of the framerail, outside.jpg is from the outside side of the framerail and bottom.jpg is where the steering box mounts)
i bought a cj-7 frame to transfer everything over onto, but the front of the frame doesnt look like my current frame, for example the steering box mounts to the cross member instead of the frame rail on the cj-7 frame and just the general appearance doesnt look the same... im trying to find out if anyone has done a similar (or identical) build or has experience in the like... if so any input would be greatly appreciated... even better would be someone in my area that would be willing to offer a helping hand, but i know that is asking a bit much.. anyways, like i said, any input would be wonderful, thankyou

 

[Bounty__Hunter]

That's going backwards in technology and frame strength. I'd recommend finding a YJ frame, you'll be glad you did.

CJ owners often swap in a YJ frame as they're more plentiful and stronger.

 

[drag0n]

That's going backwards in technology and frame strength. I'd recommend finding a YJ frame, you'll be glad you did.

CJ owners often swap in a YJ frame as they're more plentiful and stronger.

the cj frame i bought was modified and is very strong, so im not worried about that, but if a yj will fit on a cj, that means that the cj should have no problem fitting onto the rest of the yj?

 

[slo-wrench44]

ahh a fellow marine. i was in motor t down on lejeune. wish i never got out. now to the question. why not go to the local pick and pull and just get a wrangler frame. the wrangler frame is stronger, newer, should have less chance of cracks from rusting out. i think the c j frames have different spaceing on the body mounts that are welded to the frame. besides that you would have to reuse the springs and axles that cone with the cj frame because wrangler springs are wider, or so i'm told. just an opinion sell the cj frame and get a set of port a torches and head to the junk yard and see what type of deal you can get if you remove the body from it. i found a cy with a 3.5" lift that they wanted $200 for one time. you might get lucky. just my opinion. semper fi

 

[drag0n]

the only real junk yard i know around here is that one guy one guy in hubert with the offroad shop/4x4 yard, but he hasnt been very friendly (or cheap for that matter) when i tried to get parts from him in the past, other than that i dont know of any place around here. also, this ch frame has been modified with shackel reversals in the front and a small lift on it (like 2 inches). ill measure the body mounts on my jeep and then the ones on the frame to see what that looks like, but like i said, i was more worried about the doghouse with that crossmember up front and the transmission/tcase crossmemeber looks WAY off, so thats another area of concern... IT WILL WORK OUT IN THE END (says the welder)...

 

[Bounty__Hunter]

The YJ and CJ7 tubs are interchangeable from what I've seen on the web, major difference is the grille support mount. They're in the same place, but leave the grille at a different height than stock.

 

[redrooster]

I recently swapped a YJ frame under my CJ, so here's the deal on going the other way.
First and foremost, the YJ frame is 4" or so wider in the front than a CJ. This means your motor mounts won't work, and neither will the spring mounts on the axles. You would have to fab mm's and move the springs outward.
Next is that only 6 of the 8 tub mounts line up and the grill support doesn't line up either.
I haven't checked out the crossmember, but since the YJ had a different trans and t-case (driver drop) it is doubtful it would work.
My opinion, get a new YJ frame or weld and plate the crack you have. If the crack in the pics is the only one, then I would say repair it.
I got a YJ frame in good shape from Palmer Brothers in Birmingham, AL for $300. They had several. It would save you a lot of time and hassle to replace like for like. A shackle reversal is easy enough to do on your own after the swap.

 

[drag0n]

I recently swapped a YJ frame under my CJ, so here's the deal on going the other way.
First and foremost, the YJ frame is 4" or so wider in the front than a CJ. This means your motor mounts won't work, and neither will the spring mounts on the axles. You would have to fab mm's and move the springs outward.
Next is that only 6 of the 8 tub mounts line up and the grill support doesn't line up either.
I haven't checked out the crossmember, but since the YJ had a different trans and t-case (driver drop) it is doubtful it would work.
My opinion, get a new YJ frame or weld and plate the crack you have. If the crack in the pics is the only one, then I would say repair it.
I got a YJ frame in good shape from Palmer Brothers in Birmingham, AL for $300. They had several. It would save you a lot of time and hassle to replace like for like. A shackle reversal is easy enough to do on your own after the swap.

i have little-no experience with frame modification, so i dont quite know what im doing with that, that is why im hesitant to work on the frame, i have always understood if the frame is cracked, (especially on a flexing vehicle) you dont weld it, because the welds wont hold... that is the only crack, and it is rotted out on the bottom where the steering box is... im also kinda worried aobut what else may be rotting in this frame... if i do fix the old frame, anyone know someone that wants a modified cj7 frame? i paid for the frame, and im not using it as lawn furniture, as good as it does ... do you have a site/number for palmer brothers?

 

[redrooster]

I'll have to look up the number when I get back to my office.
The repair really isn't that hard if you or a friend can weld. The process is to remove the steering box and any other obstacles first. Then you clean the area around the crack to remove the rust. Next you would grind the cracks a little to give you fresh metal to weld to. Then weld the cracks up. I would then grind the welds back fush to the frame. Next you would make what is called a fish plate out of 1/4" plate steel. The fish plate would be diamond shaped like this <>. The shape gives you the maximum area to weld to. Place a fish plate over each side of the frame that is cracked.
If the fish plates interfere with re-mounting the steering box, then you may have to drill them or opt for an aftermarket bracket that you can weld on to the frame. I think Currie and MORE make a stout aftermarket bracket.
This would probably be the quickest, easiest and cheapest solution.

 

[drag0n]

I'll have to look up the number when I get back to my office.
The repair really isn't that hard if you or a friend can weld. The process is to remove the steering box and any other obstacles first. Then you clean the area around the crack to remove the rust. Next you would grind the cracks a little to give you fresh metal to weld to. Then weld the cracks up. I would then grind the welds back fush to the frame. Next you would make what is called a fish plate out of 1/4" plate steel. The fish plate would be diamond shaped like this <>. The shape gives you the maximum area to weld to. Place a fish plate over each side of the frame that is cracked.
If the fish plates interfere with re-mounting the steering box, then you may have to drill them or opt for an aftermarket bracket that you can weld on to the frame. I think Currie and MORE make a stout aftermarket bracket.
This would probably be the quickest, easiest and cheapest solution.

how about strong? im less worried about quick and easy if it compromises strength, if it is going to break under moderate (as much as i can do without several thousand dollars of rock crawling mods) stress... also, since the crack is the better part of the area around the frame, am i going to have to worry about anything putting stress on the frame while cutting it and whatnot? again, my biggest concern is how strong is it going to be?i have heard when you weld onto a frame like that, the chances of the weld breaking under flex is moderate to pretty good... am i hearing rumors?

 

[redrooster]

The frame is reasonably thick. I haven't had any problems yet with my YJ frame swap and it is welded in many places.
After looking at your pics, you may be better off with the frame swap. I suspect that this may not be the only rust on your frame. It may be deteriorating from the inside and not made itself visible yet. You may want to knock around on it with a ball peen and see what else you come up with.
The major concern I would have with your particular frame swap is that the bolts all seem to be pretty rusty. You can anticipate most of them being pretty stubborn to remove. Lots of penetrant, a torch for heating and an impact will be required. Obviously you would want to replace all of the rusty bolts with some good grade 8's.
Google search shows Palmer Brothers Chrysler/Jeep in Birmingham, AL: 205-956-8861. When I bought mine, they had 4 others. All seemed to be in reasonable shape. I wire wheeled mine, painted it black and it was good to go. I would suggest a road trip rather than getting them to ship one. That way, you know what you are getting.

 

[drag0n]

The frame is reasonably thick. I haven't had any problems yet with my YJ frame swap and it is welded in many places.
After looking at your pics, you may be better off with the frame swap. I suspect that this may not be the only rust on your frame. It may be deteriorating from the inside and not made itself visible yet. You may want to knock around on it with a ball peen and see what else you come up with.
The major concern I would have with your particular frame swap is that the bolts all seem to be pretty rusty. You can anticipate most of them being pretty stubborn to remove. Lots of penetrant, a torch for heating and an impact will be required. Obviously you would want to replace all of the rusty bolts with some good grade 8's.
Google search shows Palmer Brothers Chrysler/Jeep in Birmingham, AL: 205-956-8861. When I bought mine, they had 4 others. All seemed to be in reasonable shape. I wire wheeled mine, painted it black and it was good to go. I would suggest a road trip rather than getting them to ship one. That way, you know what you are getting.

i might have to weld it untill i can get up the money to buy all the rest of the hardware i need, but i will most definately go around the frame with the hammer and see if i can find any bad spots (insert prayer of choice here)... i appreciate all of the help

 

[TerryMason]

I put a YJ tub on my CJ (windshield back was YJ). Worked fine, except that two body mount didn't line up. I just ignored them, but I guess you could weld some on