another custom bumper thread

I am planning on building new bumpers this winter for my 5. I have plans for a winch in the not too distant future, so making the front end sturdy is a plus.

Like other folks on the forum, it will be built out of 2" x 4" x 3/16" rectangular tube.

The front bumper will have two D-Ring tow points made out of 3/4" x 2 1/2" x ~8" steel flat. This will go through the bumper and attach to the outside of the frame rails. I have power steering, so the these will stop short of the steering box. I plan on bolting them to the outside of frame with two 1/2" Grade 5 bolts.

I might also run a bolt through the front face of the bumper to the existing hole on the tab facing forward on the frame.

A few questions I would like to throw out there:

Should I run the bolts through both sides of the boxed frame with spacers inside the frame or should I just bolt it to one side of the now boxed frame? If I don't run the bolts all the way through the box with spacers, do I need to reinforce the frame/weld a plate on to add to the thickness of the frame?

Should I run a few small welds on those steel flats to the frame as insurance?

I realize that something is going to be the weakest point of the setup. However, if I am minimize that weakness, that would be great.

Once I get the front figured out, I will start planning the rear. For now, I know it will be similar but with a 2" x 2" receiver tube.

 

Yes, that would be a good way to do it. Consider using 1" x 0.250" wall DOM tubing for spacers. The 1/2" bolts will fit inside the spacers. I would weld the spacers on both sides of the boxed frame with a fillet weld. Make sure to use DOM tubing, the ID of the tubing will be smooth with no weld seam.

That would be better than no spacer at all, but just as much work as making spacers.

This would defeat the purpose of a "bolt on" bumper.

Take some pics when you start, good luck.

 

If I did decide to weld a plate on the frame rather than creates spacers with DOM tube, would 1/8" steel welded to the outside of the frame work? I am partial to this method because I am not sure I can get the spacer in with a good enough weld.

I was thinking that if I did a few welds, it would help and if I needed to take it off, I could grind down the welds. Yes, it would be a PITA, but I can't think of a reason (right now) why I would need to remove it. I haven't touched the bumper that is on there now for a long time.

I will be sure to snap pictures and post them. I have yet to buy the steel, but plan on doing this in the coming weeks.

 

Whenever I have to spend extended time under the hood or have to remove the grill I pull my bumper. It's nice when it's only 6 bolts.

I don't know what I'll do when I get my PTO winch installed. R)

 

First of all it seems your going to do all the attaching of the bumper in the space just forward of the steering gear is that correct?............If so that area by itself without no other form of reinforcement traveling back to the first cross member at the radiator I believe will not be strong enough.
Tow hooks and a winch can put an immense amount of force on the front frame rails...........especially one that is only made out of .120 thick steel weakened by rust and welded 47 years ago. Coming up the outside of the frame on both sides with a plate say 3/16" - 1/4" thick that extends back to about where the shock and first cross member is should act as a good base for the strength that will transfer the load rearward ......... you'll need this if you ever get in a tough pull where the Jeep is buried in Mud!
Now your 1/2" bolts ( and I would use Grade 8 ) would be on shear to that long plate and the short section of front frame rail and would be much stronger..............just my opinion!

 

Here is mine. 1/4x3 flat stock run thru the bumper, welded front and back, and bolted to the frame. The tow points are made 1" wide by welding 3/4x3 to the 1/4 and the face of the bumper and then profiling them together with a flap disc on the grinder.

The inside of each frame rail is boxed with 3/16 and all mounting bolts are sleeved with tube, except for the forward most 3/4" bolts. Those bolts utilized existing holes in the frame. The picture is an illusion and there are 2 not 3 bolts holding on the bumper. Should be plenty strong!

 

I welded my bumper to the frame as I wanted to do everything I could to inhibit frame twist. I had to raise my winch in order to clear the steering box so I started with a piece of 4" x 6" x 1/4" rectangle tubing and split it to get two sections of angle. This gave me the rounded corner that looks better than using angle iron. I used DOM tubing to sleeve the frame for the 1/2" grade 8 bolts. All the plate is 1/4" and the front of the winch mount is bolted to the top of the bumper with 3/8" grade 8 bolts. This adds shear strength to the front of the bumper and frame.

 

Wow, where has the time gone.

I finally got all the metal and have started working on this project.

I cut the front bumper(55") and the rear bumper (54"). I will get some pictures later this weekend. I liked how 55" looked, then second guessed myself and made the rear 1" shorter. I am still debating on taking an inch off either side of the front to make the overall 53".

I sourced some 3/8" flat from the local machine shop and I will weld that to the outside of my frame rails going back to the cross member as Tarry had recommended. I thought it was 1/4" at first, but 5 bucks for a 4 foot length works for me. I am trying to keep the overall weight down, but this should only add ~1.5 lbs/side over the 1/4" flat of the same length.

The machine shop is going to cut my 3/4" tabs in the next few days and then I will notch the bumpers to slide those through.

My next question is: if I plan on a winch in the future, how would you build this to later incorporate that? I think I would have to do something similar to Posi's setup, but If I put a 1/4" piece down the outside of the frame, I am going to be adding quite a bit of metal at that point to the outside of the rails.

I.E.

3/8" reinforcement flat
3/4" bumper mount
and then
1/4" winch mount

Is it just me or does that seem like too much?

Thanks as always

 

erhuff,

Here is some Idea's for your bumper.........The tow brackets on the rear go completely through the tubing and are welded on both sides.......as well as the square tow hitch.
It would not do much good using 3/8" plate to extend the bumper brackets fore or aft since the base metal or frame your attaching that too is only .125 +/- thick............better to spread the load out over a longer distance by reaching back with some .125 or .188 flat bar stitched welded to the chassis back to the next intersection of strength and continuity as shown in the front end picture. In that photo I grabbed and welded to the three anchor pins that exit the frame that are attached to the radiator cross member...........My tow hooks on the front are the large blocks on top of the frame.
Then do a .312 or .250 plate coming off the bumper properly attached w/ gussets and then attache it to your frame.............the bolts going through the frame should be sleeved if that section has been boxed or is now hollow.......the point again is to distribute the load by reaching back.
These methods of course are for extreme towing .......But in my eyes, what else is there?

 

Tarry,

Thanks for the pictures and ideas.

The 3/8s bar was going to work exactly as you have the 1/4 bar on your rails, but given the size of the 3/8" bar, I just ordered some 1/8" bar to run back to the cross member for both the front and rear bumper.

I will stitch weld that on and that should also help stiffen up the front end with power steering as well. Not much in the way of pictures yet and this weekend was devoted to moving someone in.

Since I have longer pieces of 3/4" bar, I am still going to run that through the bumper then bolt that to the newly reinforced frame. My next question is: how do you recommend I cut the holes in the bumper? My initial thought is to use a cut off wheel. It looks like you had yours milled and it looks very clean. I don't have access to that machinery, so I think a cut off wheel and some careful/precise measurements are my only option.

Thanks

 

I used .125 to plate the outside.......

A small cutoff wheel would work for the longer run ( depending on the diameter of the wheel) but probably not for the short side............You could also drill say a 3/8" hole at the corners of the pattern sized hole you need , just so the OD radius of the drill hole size touches the Inside of the pattern.........basically your center point of the hole wants to be 3/16" inside or away from the edge for a 3/8" drill sized hole , then take a "Good" variable speed Jig Saw and say a 14-16 tooth metal blade and connect the corners............if the blade is to long to get in the tube cut the end off with your cut off wheel........Doesn't hurt to cut it on the line or towards the outside of your line as the weld will fill up that little gap. Your bar may need the square edges ground off just a little to get it to pass through. Make sure both holes on either side of the tube line up..........

 

I did my 3B similar to what Terry did. It has 1/4" plate on the outside extending back to the axle centerline and 3/16 plate on the inside from the cross member to the bumper. I just used my stock bumper and boxed it with 1/8" outside the frame rails and 1/4" inside the rails. All of it is welded together.



You could go ahead and set it up for whatever winch you plan to use. The mount spacing is available on-line for most winches these days. I built my winch mounting and fairlead right into the bumper and I also fully plated the winch cable slot.


Just more food for thought.