Roll bar and body tub

So I am toying with the idea of swapping out my steel tub for a Kevlar one in the area. I think it's make by Shell Valley? Don't quote me on that. My steel tub is not in terrible shape, however, it does need the front floorboards repaired and inside the under-seat compartment has been shoddily repaired with fiberglass. Ok, so my dilemma is if I do decide to replace the tub, where and how would I mount the cage? Would the kevlar tub with some mounting plates hold up in a low speed roll over? Also if I tie it into the frame am I just asking for frame/body damage? I would use the way way back machine to research this but I figured opinions on the subject may change over time , any help would be appreciated!

 

Everyone who actually off-roads their Jeep should tie the cage into the frame.

 

Cage needs to be tied to the frame

http://www.polyperformance.com/shop/Cage-Tie-In-Kit-p-433.html

even has pictures.

I don't like welding the tube straight to the frame. prefer a plate with <> shaped ends, 3/16 thick.
Also the bushing can be attached to the frame and solid mounted to the body,

 

Yea, I have a little issue with welding directly to the frame as well. I think it was on Boyink's site I read that frame/roll bar tie in can cause stress fractures in the frame? Any thoughts on that?

 

Don,t worry about it. It is just steel. It just requires a good standard weld job. A six or eight point cage will add rigidity to the frame.

 

Most of the cages I've seen have some sort of attachment point that allows movement between the frame and the cage. CJ's were made to twist a bit. It helps off road. If you weld to a frame, the jeep still wants to twist but the cage (and the welded point) prevents that.

I'd design some slight movement in it that allowed the frame to flex.

 

how do you tie the floor mounts to the down tubes of the cage to the frame???? I have headers and the exhaust is all in the way..I was going to weld a big plate to the bottom of the down tubes and then go to the mount on the floor but that is not solid, soild..the middle mounts are kind of doable with a kicker tube off the frame .and the back is easy . I have put this off for years and have bad cracks just about everywhere.. the frame is fixed now for awhile and I 'm redoing the middle section that was bad,not rusty just all torn up.,,,,,,,,,,,,,,,,,,,,,,,,, but it does flex like mad!!!:twisted:

 

Find yourself a local 4x4 club. You will find folks there who have modified their jeeps many times and have good fabricating skills. Everybody seems to tie their cages into the frames slightly differently. It would help you to hang out with them, shoot the bull, have some fun, and as a bonus you will get good ideas on how to improve your Jeep, as well as make some friends to wheel with. Even though most will not have an old CJ, basic fabricating skills still apply.

 

I did, and I have the oldest rig by far ,,,,thats why I'm here ,,,,,so how did you tie the cage down tubes to the frame in the front. there's quiet a space there........

 

You have to find a way to run a bar out there from the frame with a plate sitting on top of it. Mine also ties into a big piece of angle iron I use for rocker panel protection. I also have two more bars running out there to the big angle iron from the frame to help support it. Since that front hoop is in such a bad place, and the fact that the bar that goes out there may not be as big as you want it due to exhaust interference, you just have to tie it all together as much as you can. You may want to consider (I didn't) running a tube that ties into the front side of the front hoop legs just under the dash, through the firewall, into the engine compartment, and attaching to the frame near the front shocks or radiator. It can also serve as a upper shock mount, or you can run bars above the engine to protect it, or the radiator. You can also tie into the front bumper. Your imagination is the limit there. --Also-- If you haven't already, you also may want to run a bar from side to side near the top of the dash connecting the front hoop legs together. That stiffens those legs up alot. Another place that I tie my front hoop into is I run a bar ( inside the passenger compartment) below the door opening back to the main hoop.