Has anybody built their own frame from scratch? - JeepForum.com
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post #1 of 21 Old 11-21-2019, 05:44 AM Thread Starter
skizriz
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Has anybody built their own frame from scratch?

I've been kicking this around for awhile now. My frame is twisting itself to death. There are a few things I would also like to change along the way.

I should also note that I am just about ready to pull the plates off of the old girl for good and be a trailer queen.

Looking for some tips and ideas.

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post #2 of 21 Old 11-21-2019, 07:13 AM
firegod33
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Much like building trailers, by the time all is said and done, you'd probably be time and money ahead by just buying an aftermarket frame. Steel, welding wire/rod, abrasives, paint, and other odds and ends add up quickly, not to mention the time involved to get everything perfect.

Earth first... We'll Jeep the other planets later.
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post #3 of 21 Old 11-21-2019, 09:11 AM Thread Starter
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Only problem is getting exactly what i want.. Mainly a little higher in the wheel arches as I'm limited to about 2" of up travel already, and want to lower the jeep a little bit. I also want a few more inches of stretch, both front and rear. That kind of eliminates a replacement frame.

I have thought of just getting the two aftermarket frame rails only, and going from there.
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post #4 of 21 Old 11-21-2019, 09:18 AM
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Originally Posted by skizriz View Post
I have thought of just getting the two aftermarket frame rails only, and going from there.

This is my plan for the '6. eventually ordering a set of frame rails from TDK and then spacing them to fit the spring perch's for the full width front axle and putting in the cross members where I need/want them. SIL's cousin lives just down the road from TDK and there is no sales tax in MT, will pick them up next time I visit my brother in Missoula.

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post #5 of 21 Old 11-21-2019, 09:45 AM
StoneTower
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TDK also make hybrid frames that use TJ suspension components. It would be nice to have a long arm suspension under your CJ.
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post #6 of 21 Old 11-21-2019, 11:18 AM Thread Starter
skizriz
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TDK also make hybrid frames that use TJ suspension components. It would be nice to have a long arm suspension under your CJ.
Nah. I like my leaf springs. It works well, why change it.
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post #7 of 21 Old 11-21-2019, 11:23 AM Thread Starter
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Quote:
Originally Posted by skizriz View Post
I have thought of just getting the two aftermarket frame rails only, and going from there.

This is my plan for the '6. eventually ordering a set of frame rails from TDK and then spacing them to fit the spring perch's for the full width front axle and putting in the cross members where I need/want them. SIL's cousin lives just down the road from TDK and there is no sales tax in MT, will pick them up next time I visit my brother in Missoula.
Thats a good option to save a ton of work.

Wonder how the YJ or even TJ arches would compare? Ill have to check the dimensions.

Another thought I had. A buddy of mine has a back half kit laying around he would sell for cheap. One at the rear, and another at the front, and it would be just straight 2x4 rails for me to deal with. Im not worried about kicking the rails wider at the rear, it would be easy to just outboard the rear spring mounts.
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post #8 of 21 Old 11-21-2019, 02:07 PM
Fourtrail
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Quote:
Originally Posted by skizriz View Post
Thats a good option to save a ton of work.

Wonder how the YJ or even TJ arches would compare? Ill have to check the dimensions.

Another thought I had. A buddy of mine has a back half kit laying around he would sell for cheap. One at the rear, and another at the front, and it would be just straight 2x4 rails for me to deal with. Im not worried about kicking the rails wider at the rear, it would be easy to just outboard the rear spring mounts.

The CJ-6 frame rails are straight and 10" longer than your '7, may check the wheel arches and then cut that you need to out of the middle. I can try to measure my wheel arches and compare to dad's 7 over the weekend.

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post #9 of 21 Old 11-21-2019, 03:17 PM
Fourtrail
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Don't know if you have read it yet, but Mieser's build thread over on Pirate has a ton of good info on building your own frame, his is for a Flatty, but most will info is the same.


https://www.pirate4x4.com/forum/jeep...willys-mb.html

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post #10 of 21 Old 11-21-2019, 05:00 PM Thread Starter
skizriz
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.[/quote]


The CJ-6 frame rails are straight and 10" longer than your '7, may check the wheel arches and then cut that you need to out of the middle. I can try to measure my wheel arches and compare to dad's 7 over the weekend.[/QUOTE]

Thanks, i appreciate it. I kind of assumed that most of the CJ frames would have just about the same basic arches. Guess they didnt really plan on much up travel.

The front is where i really need some more arch for my steering. As thin and flimsy as it is, im afraid to C notch it for more room. Plus without moving the front axle forward a bit, my crank pulley and steering ram would be fighting for the same real estate.

This frame just twists and flexes so much, even with the cage tied in at 8 points, that it sounds brutal on the fiberglass tub when flexed out.
A nice 2x4 .. 3/16...tube would be ideal to work with.
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post #11 of 21 Old 11-21-2019, 05:21 PM
Fourtrail
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Originally Posted by skizriz View Post
Thanks, i appreciate it. I kind of assumed that most of the CJ frames would have just about the same basic arches. Guess they didnt really plan on much up travel.

The front is where i really need some more arch for my steering. As thin and flimsy as it is, im afraid to C notch it for more room. Plus without moving the front axle forward a bit, my crank pulley and steering ram would be fighting for the same real estate.

This frame just twists and flexes so much, even with the cage tied in at 8 points, that it sounds brutal on the fiberglass tub when flexed out.
A nice 2x4 .. 3/16...tube would be ideal to work with.



I am in the same flex boat, had to replace the front cage tie in's with bushing mounts because I was ripping them off of the frame. this winter I have to build some kind of slip joint into the steering shaft, the frame from the front cage tie in forward will flex enough to pull the steering shaft off of the steering box.


as for real estate up front, I have two shiny spots on the draglink where it touches the crank pulley at full flex each way. My motor could use to go back a few inches, but with the np203 length, I don't want to loose any rear driveshaft length. When I do the new frame, it will hopefully sit quite a bit lower and now that the tub has been beat and cut, I will take the plunge and cut the center out and raise the drivetrain up to get a flatter belly. If I can keep the center clearance now with the drivetrain tucked up, the Jeep will sit about 6" lower overall. That and I will push the front axle forward a bit for clearance.

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post #12 of 21 Old 11-21-2019, 07:52 PM Thread Starter
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I can feel it in my steering wheel when it flexes, never pulled apart, but I can feel it pushing and pulling in my hands. That small front section is what worries me the most.

I never gave much thought to a YJ frame. Fully formed, it should hold up a lot better. Wouldn't be hard to strip one down to bare frame rails and start with that.

Really looking at all options. I have had to weld the factory seam on mine a few times now, and have had to fix a couple of cracks. Eventually its going to get to the point where I have to replace it. I'd like to have something on the back burner for when that time comes.

It would be nice to just go and drop a few grand on a new TDK custom bent frame, but that just isn't in the budget. A few more years, and I just may go and buy myself a buggy.
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post #13 of 21 Old 11-21-2019, 09:02 PM
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You'd be amazed what a PITA it is to build a frame. There are a million little things to it steering box mounts, cross members, body mounts, brake line brackets, parking brake brackets....

Rather than build your own frame, just cut off the back of yours just after the forward rear sprint hanger. You can cap it off and weld some tube to it there. You get into what we used to call hybrid rigs, part normal rig, part buggy.

If you insist on doing it anyway, 3/16" is way heavier than you need. 1/8"/11GA will do fine.

Old article vaguely related to the hyrbrid idea: http://www.4x4wire.com/tech/body/tubeitout01/

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post #14 of 21 Old 11-21-2019, 09:39 PM
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The frame was intended to twist as it left the factory, it was never intended to be rigid.

Your 38" tyres, Dana 60 axle and 360 V8 are far too much for the old frame, you need something a whole lot stiffer.

Is your roll cage tied into the frame and if so do you believe you have gone far enough? For stiffness you want to have metal as far from the frame as possible to maximise the sectional stiffness, which is a function of not just mass of steel but distance from the neutral axis. Having a deeper (even thinner) frame rail would help, but that causes space issues, the main other option is to add metal above the frame rail such as a roll cage that is fastened at several points along the rail. By tieing the two frame rails together, if the roll cage is rigid, you get them to work as one section. Have you thought about adding metal around the engine bay ( like a hoop, just behind the radiator) and tieing this back to the roll cage? I have never tried this on a CJ, just a thought that a semi-spaceframe built from the frame and roll cage extending through the length of the CJ is a stronger answer to flex than a replacement frame which was not designed for your rig's prodigious abilities.
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post #15 of 21 Old 11-21-2019, 09:39 PM Thread Starter
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Quote:
Originally Posted by TerryHowe View Post
You'd be amazed what a PITA it is to build a frame. There are a million little things to it steering box mounts, cross members, body mounts, brake line brackets, parking brake brackets....

Rather than build your own frame, just cut off the back of yours just after the forward rear sprint hanger. You can cap it off and weld some tube to it there. You get into what we used to call hybrid rigs, part normal rig, part buggy.

If you insist on doing it anyway, 3/16" is way heavier than you need. 1/8"/11GA will do fine.

Old article vaguely related to the hyrbrid idea: http://www.4x4wire.com/tech/body/tubeitout01/
It's nothing surprising to me, or new to me. I've built this jeep from the frame up a couple of times. I've been through two bodys, two different frames, three sets of axles starting with stockers and ending with a 14 bolt and Dana 60 that I narrowed myself. Built the cage, swapped the motor, transfer case, built the driveshafts, installed gears,built my steering, etc, etc, etc....Only original parts are the grille, transmission, speedometer and steering column.
Nothing about building a frame scares me, just looking for some ideas from others that have done it already.

Basically other than the original frame rails, there isn't a part on this jeep that I haven't built or modified to be stronger.

Back halfing it still doesn't help me any with the main problem of the stock frame twisting too much, mainly from what I consider a very weak front half.
Heavier than I need, sounds just about enough.

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