Designing the tubing on my MJ

[BPB]

This is what i am working with. A 1990 Jeep Comanche, Never mind the rear bumper, I broke it so i am going to remove it.

 

 

This is the basic idea of my build. Diagram A is the part that goes right behind the cab, I am going to run it a little above the cab so that I can add a front exo later. Am I going to need to reinforce the frame where it mounts? If so what are your suggestions?

 

Diagram B is from the back. The blue is the frame. The red is where it mounts to the frame. What do you guys think, Any suggestions?

 

 

Next question I started building myself a bumper before I wrecked my truck, the bumper is the width of the bed made out of 3/16 wall 2x5. Should I use it as a base in the back? like diagram B, or should I build something new that is narrower? Mind you that I am going to full widths. I am going to add fenders later so that it is streetable.

 

[pingpong]

First we need to know what kind and size of tubing you are going to use. If you plan on going full width.. why not shorten the frame up a lil, and move the front mount forward, and move the rear forward as well so you could use xj lift springs :idea:

 

 

On that note... A fuel cell that is properly setup, wil look much better then the gas tank sitting there.

[Pete M]

You'll definitely want to use an adapter plate when joining tube to the sheetmetal frames on an MJ so you can spread out the forces and not just tear the bar from the sheetmetal. These are some of the various designs on my 88. My rollbar is only expected to survive one good roll. It's no rock buggy. :D

 

rollbar front legs. The angled steel is just a crosscut of 3x5 box steel tube I found in the scrap bin. That is welded to a ~4x6 piece of 1/4" plate and that is welded to the frame.

 

 

Rollbar rear legs. They are not actually welded to the frame, but rather the adapter plate (1/4") is bolted to the rear bumper plate (also 1/4" steel) and through the frame with a 3/4" grade 8 bolt.)

 

And my rocker guards. These actually penetrate through the frame and are welded to both sides.

 

 

 

 

The finished bar with tire carrier.

[BPB]

Pete :bowdown: I like that. I will weld quarter inch plating to the frame I an then going to have the tubing come straight off of that. I want to be able to integrate rockrails into the hoop around the back of the cab. To answer the tubing question. I am using 1.75" 120 wall DOM tubing. I am also going to the bottoms of the X go from the top of the frame to the adjacent corner. What is the difference between what I am planning on and a fuel cell?

[pingpong]

The difference is rollover protection and looks. Right now if you roll over.. your tank will leak. Might even leak in a flop... I know mine did :eek:

[BPB]

Ok, well like I said i am having a diamond plate box built to go around the tank. If it leaks up side down or in a flop I guess that I had it coming, I bet that I could find or make back flow valves. Plus right now gas is practically free!!! :banana: :banana: :banana: :banana: :banana: :banana: :banana:

 

Any other comments on the rear tube design???

I am buying tube, a new hole saw, and a new bottle for my welder Friday!! :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana:

[project88mj]

what diamerter tube are you going to use and how thick will the pipe walls be?

[BPB]

I am using 1.75" 120 wall DOM tubing.

 

Here is my new idea for the back hoop, the red is the frame