I just purchased a 72 CJ5 frame to replace the one I broke last summer. I understand that there are a few updates (places to box, etc..) that I can make to the frame to help strengthen it. Does anyone know exactly what needs to be done? I know that you should box above the real spring hanger but not sure how much to box? Any feedback would be helpful.
Thanks,
Tim
:beer:

I would say box everything between the bumpers:flipoff2:

i would box from front to back. if you don't, it will just crack where its not boxed. ;)

Originally posted by Weezer
I would say box everything between the bumpers:flipoff2:

and strap it:flipoff2:

I boxed everything from the front bumper to just after the rear spring hanger on my 72. It turned out really good and it is MUCH stronger

I boxed everything front to back, ALLL the way to the back and then welded in a new rear crossmember and new second most rear crossmember. I also added strapping from on end to the other on both sides in two continues pieces.
Its friggen stought. I never had frame cracks to begin with and i didnt want any.

Used 4x2 angle iron where the springs attach. Nothing else hasn't cracked in over 4 years. Someone also redid the floor in my jeep at some time and was very, very well made. They used small c-channel and plate steel. I believe that the floor keeps the frame form twisting around.

I have had several people tell me NOT to box the entire frame. They said that frame flex is part of the design and it should not be eliminated by boxing the entire frame?

If you dont box the whole frame....It will just crack where you dont box it! It doesnt take anything away from the frame.

my thoughts on frame flex... but first, my frame is about 3/4 boxed and 100% strapped top and bottom.

Frame flex is bad, isn't flex what your suspension is supposed to do??? and when your frame flexes, what happens to your body?

Go to the closet, take one metal coat-hanger, take one sheet of aluminum foil and shape it on the coat-hanger to completely cover every inch of the triangle part of the coat-hanger. Now tape the foil down about every two inches or so. Okay, now think of this setup as your jeep frame and tub (hanger=frame, foil=tub) now flex the coathanger in an articulation type movement. Notice what is happening to the foil:eek::eek:, now just think of it as your Jeep tub:eek::eek:

now, take two coat-hangers and solder them together, attach the foil and apply the same pressure to simulate articulation;) sure there will be some flex, but not to the EXTREME that was there originally... I hope you get the picture, frame flex bad, spring flex good:grinpimp:

body flex worse:D You should see what my body has turned into because of other things flexing besides the suspension. i.e body lift, rollbar

Originally posted by HighHooder
my thoughts on frame flex... but first, my frame is about 3/4 boxed and 100% strapped top and bottom.


I've tried searching for info on strapping frames, but came up pretty much empty (searching for strap AND frame). What do you mean by strapping. I understand boxing the frame, but strapping? :confused: :confused: Thanks, Bret

Adding/forming steel to the top and bottom of the frame.

Ahh, now I understand..:rolleyes: Thanks for the info:D

Originally posted by hubeid


I've tried searching for info on strapping frames, but came up pretty much empty (searching for strap AND frame). What do you mean by strapping. I understand boxing the frame, but strapping? :confused: :confused: Thanks, Bret

I wish I had some photos to show you (:flipoff: photopoint) but basically, you take a piece of flat bar an 1 1/2" wide by your choice of 3/16" or 1/4" and welding it to the top and bottom frame rails. I used 3/16" on my cj3b, while I have a 2 friends that both used 1/4" on their cj5's.

edit: found a pic on another site if you look real hard you can see the strap on the top and bottom of the frame. You can also see the alternating stitch welding pattern of inside, outside, top, bottom, that REALLY helps keeping the frame straight while the welding process keeps trying to bend it in all directions

http://www.film.queensu.ca/cj3b/Photos/Tech/Pinto/McHughFloorSupports.JPG

I did this when I installed MORE frame plates on my CJ.
We used 1/4" on top and bottom and stitched every two inches.

:cool2: :cool2: Thanks for posting the pic HighHooder. I'll add this to my list of 'mods' for my frame. I've got quite a bit of work to do to this thing, so I appreciate the info:D Thanks, Bret

I agree frame flex is bad....couldn't believe my frame flex the first time I put a hi jack on the bumper....:eek: the corner of the jeep went up 5" before the rest would catch up.....my power steering would actually flex the frame....every bodymount was cracked or tore :( ....I'm going to box my frame alright...

another

Here's the best illustration of frame strapping I've seen ...

http://www.monsterslayer.com/jeep/Pics/FrameStrap.jpg

... I don't remember the author - but thanks to him ... :)

Originally posted by Jaffer
Here's the best illustration of frame strapping I've seen ...

http://www.monsterslayer.com/jeep/Pics/FrameStrap.jpg

... I don't remember the author - but thanks to him ... :)

that's exactly the process I used, 'cept I used more clamps and the straps run FULL LENGTH of the frame on top and on the bottom they butt up aganst the spring/shackle hangers.

So should I pull the hangers and cross members off before strapping?

Originally posted by tlancaster
So should I pull the hangers and cross members off before strapping?
yes, I pulled my crossmembers off, but left the hangers on. But if you are up to it I would take every obstruction off the top and bottom frame rails and use one piece of strap top and bottom.