Custom rock rail questions

This past weekend when wheeling with one of my friends we got talking about various things and we got on the subject of making rock rails for my 91 4dr XJ. I've been doing some searching and trying to find the best way to make them and attach them and I have a few questions.

My plan is to make the main rails out of 1/4" 2x2 tube, make an angle frame mount bracket out of 3/16" plate and attach it with 2 bolts in the side and 1 or 2 bolts in the bottom of the frame along with a 1x1" square tube bolted to the pinch seam. Here is where the questions start, what should I make arms that go from the frame to the rail out of, I was originally thinking some more of the 2x2", but from looking around I'm seeing some of the aftermarket companies are using thick plate or 1x1", and if I could get away with just the 1x1" it'd save some money and some weight. If I need to add a third frame-to-rail member to use the 1x1" I would be up for trying that. Second question is, what to use for bolts, I was planning on using self tapping bolts into the frame, but how big of a bolt. As for the pinch seam I was just going to use 6 small grade 8 bolts (not self tappers) and I was wondering if I should use 1/4" or 3/8" bolts.

If anyone sees anything I'm overlooking, please let me know. Thanks in advance for the responses.

There has been a lot of talk on the board, first do a search you should find a ton of info.

I have the C4x4's, and they are mounted to the frame rail with 3/16 plate, rear to the front leaf mount and the front to angle.

For the frame rail, I would get a piece of 3x3/16 angle and run that down the lenghth of the frame rail. Then weld the 1x tube to the angle. Use the 3 attach points to the frame rail rather than the standard two.

Otherwise your incorporating the pinch seem, and weight should be be a major concern with the materials your using. If you wanted to shave off some weight use 2x2x.188 instead of the .250. I have only seen rockrash on mine, no dents on the 2x2x.188 tube.

I used 1X2 .188 square tubing on mine. Why give up an extra inch of ground clearance if you dont have to. I doubt 2X2 tubing will be any stronger. Unless you are planning to use the sliders for air storage. I store air in mine but I have no compressor and no way to get the air out of them. Use the same tubing for the legs that go to the frame and attach to your liking.

HTH, Dan

I used the exact same material 2x2 0.25" wall and turned it 45 degrees so you have a nice thin edge to pivot and slide on - keeps the high lift on there nicely too...

I just ran flat plates on the frame and then used 1" wide 0.188" flat bar for the pinch seam mounts - 9 x 1/4"pinch seam bolts per side, 12 x 3/8" frame bolts per side - and then when I did my cage I welded the plates to the frame...

The rails are nuke proof - they have some serious abuse and barely even show the gouges in the steel - 0.188 would have bent long ago with the hits these have taken...

Matt

A nice old pic


Frame mount:


And now:

I am in the process of making mine as we speak. I found that a piece of 4x2x188 bolted directly to pinch seem works great for coverage. I will use 3x3 angle to distribute the load on the frame rail ( for lack of a better term) with 2x2 legs going from the angle to the 4x2. My choice of materials was influenced by the fact that I have thousands of feet of 3x2, 4x2 ,and 2x2. I am kinda cheap and would rather use the stuff I have around. The 4x2 tubing really is a good fit, and it leaves a small platform I will be able to stand on. Another benefit is I can bolt the 4x2 to the pinch seam and build the rest right on the Jeep (everything fits perfect that way).