Rear Bumper Fabrication Question (1 Viewer)

[Pascoscout]

I did 3/8" plate for mine and it's been fine. I believe some of the other kits are using 3/16" so if designed right it will hold.

Here's my bracket that wraps around two side of the frame. I also made a second connection point at the front of the side wings to keep them from flexing. Glad I did as those seem to take a lot of hits.

And yeah it will take time but it is really satisfying knowing you designed and built your own.

 

[davegonz]

Do the DIY 4x4Labs kit. Saves time b/c it's pre-cut and money because you weld it yourself. It's also modular and you can mod/upgrade as you go. Best value overall IMHO. I've built some for my old 100 and 4BT80 and was not disappointed.

 

[ScratchedFJ]

Continued with the design tonight. Added the basic swing arms with 75A durometer polyurethane bump stops and latches. Made a few minor geometry updates. I need to take some measurements tomorrow to ensure my swing arm spindles are in the correct position relative to the brake lights and rear hatch doors. Current rough estimate is looking like about $1k for pre-fabbed stuff (spindles, wheel mount, latches, bump stops, trailer hitch receiver), laser cut plate pieces, and main bar. I'm not sure if I'll make my own jerry can holder or just buy one and weld it on.

 

[Pz10420]

I recently built dual swing outs and used spindle from EMS offroad. They are pretty cheap at only about$50 a piece and I am very happy with them. They use bearings and are greasable. I've only had them on for about 3 months so far but they haven't wiggled or budged at all.

 

[ScratchedFJ]

I recently built dual swing outs and used spindle from EMS offroad. They are pretty cheap at only about$50 a piece and I am very happy with them. They use bearings and are greasable. I've only had them on for about 3 months so far but they haven't wiggled or budged at all.

Thanks for the recommendation! Did you happen to measure the spindle diameter before you installed it? Their website didn't appear to list the diameter.

 

[Broski]

Your design looks straightforward and simple, in the past I have pushed the hitch in all the way on bumpers that I have built. you can reach under to put the pin in it's not that hard after a few time it second nature and super easy it has a much cleaner look and you won't hit you knee on it. If you are going to use the hitch for towing or a recovery point then it needs bracing in the back.

In this picture you can see the hitch brace on mine it's angled for side load , I use it for my rear recover point

The main mount that I fabricated, made out of 1/4 plate, it utilizes the three spare tire mount points and three of the rear bumper mounting points on each side. It has taken some serious hits with nothing more then some scratches.

 

[ScratchedFJ]

Your design looks straightforward and simple, in the past I have pushed the hitch in all the way on bumpers that I have built. you can reach under to put the pin in it's not that hard after a few time it second nature and super easy it has a much cleaner look and you won't hit you knee on it. If you are going to use the hitch for towing or a recovery point then it needs bracing in the back.

In this picture you can see the hitch brace on mine it's angled for side load , I use it for my rear recover point
View attachment 2515029
The main mount that I fabricated, made out of 1/4 plate, it utilizes the three spare tire mount points and three of the rear bumper mounting points on each side. It has taken some serious hits with nothing more then some scratches.
View attachment 2515030

Yeah I had been trying to think of how to brace the back side of the tow hitch. I had not considered the mounting points for the spare tire hanger but I really like that idea and am going to investigate and measure those locations today! Thanks for that idea.

As for having the tow hitch mount be flush, I could not get to the pin on my design if it was flush mounted because I'm using a 2"*5" main tube. So, my thought was to potentially extend the angular side wings past the face of the main bar and then run a boxed section under the tow hitch all the way across. This would only be for aesthetics though and add a good amount of weight so I'm not sure if I'll do that.

 

[davidp14]

this is a great thread! Really impressed with everyone's work here. I'm still very much a novice welder but I hope to be at the level of some of you guys here and be able to build my own bumper soon.

Following along for learning and inspiration.

 

[Broski]

Yeah I had been trying to think of how to brace the back side of the tow hitch. I had not considered the mounting points for the spare tire hanger but I really like that idea and am going to investigate and measure those locations today! Thanks for that idea.

As for having the tow hitch mount be flush, I could not get to the pin on my design if it was flush mounted because I'm using a 2"*5" main tube. So, my thought was to potentially extend the angular side wings past the face of the main bar and then run a boxed section under the tow hitch all the way across. This would only be for aesthetics though and add a good amount of weight so I'm not sure if I'll do that.

I would not be afraid to notch the back side of the tube enough to access the pin. Also the tube well be much stronger then the plate in you drawing.

 

[ScratchedFJ]

I would not be afraid to notch the back side of the tube enough to access the pin. Also the tube well much stronger then the plate in you drawing.

Here is a cross-section view of the hitch receiver. I would really have to notch and pocket the main tube to be able to get a pin in if I have the receiver flush. So unfortunately I think I have to go with having the receiver protrude.

I could pocket under the receiver and plate that in though (which I kind of like the idea of). I'll try modelling this idea up at lunch.

 

[Heckraiser]

Just drill the hitch pin hole farther back so you can reach around/under the bumper. There are lots of hitches that have a long shank to accomodate 3+ inches of receiver length. My hitch sticks out really far from the pin hole and it's just an off-the-shelf unit from the part store. I can take a measurement.

 

[Heckraiser]

Here you go. This hitch is from O'Reilly or Napa. You can slide it in 5.5 inches to the center of the pin. Just drill a hitch pin hole a couple inches back. Problem solved and you'll definitely appreciate the flush mount for looks and not knocking you knees on it.

 

[Pz10420]

Thanks for the recommendation! Did you happen to measure the spindle diameter before you installed it? Their website didn't appear to list the diameter.

I did measure it and I want to say its 1.25inch but don't quote me on that. But I tested it out after building it, installing my 33inch spare and my 200 lb frame standing on it and didn't feel much movement, so I think it should be sufficient.

 

[ScratchedFJ]

Here you go. This hitch is from O'Reilly or Napa. You can slide it in 5.5 inches to the center of the pin. Just drill a hitch pin hole a couple inches back. Problem solved and you'll definitely appreciate the flush mount for looks and not knocking you knees on it.

View attachment 2515172

Oooh good point. I'll measure my hitch that I have and see where that puts me! Thanks for helping!

 

[Pascoscout]

Are you planning to cut off the rear factory cross member? You won't need it if you do the tube for sure. If you're leaving it a plate will work fine there and save you a lot of weight.

I used the spindle set from Ruff Stuff, think it's 1-1/4". It's super stout and the bearing are available at any trailer parts supplier.

Your design is looking good. Few things I have found that may help:

Add a brace between the front part of your side wings and where your bumper bolts to the frame.

I found that mounting the latches on a an angle results in a much easier to open/close set up, I am using a straight latch though vs the 90 version you have shown so may be a different result.

On the ends of your arms, at the stops, you'll want a tab of some sort to stop the swing and give the latch something to pull the arm up against. You could add a small plate to the bottom of the tube that hits the stop that the arm rests on, that's how mine is designed.

I assume the poly stops your referring to are what the arms rest on, not the swing stops for the open position that are near the spindle (which I don't see but you will need)? I started with a hard poly stop near the spindle and found it only lasted a few weeks. Ended up replacing it with a steel stop recently and much happier so far.

Keep up the good work, look forward to seeing this become a reality.

 

[ScratchedFJ]

Are you planning to cut off the rear factory cross member? You won't need it if you do the tube for sure. If you're leaving it a plate will work fine there and save you a lot of weight.

I used the spindle set from Ruff Stuff, think it's 1-1/4". It's super stout and the bearing are available at any trailer parts supplier.

Your design is looking good. Few things I have found that may help:

Add a brace between the front part of your side wings and where your bumper bolts to the frame.

I found that mounting the latches on a an angle results in a much easier to open/close set up, I am using a straight latch though vs the 90 version you have shown so may be a different result.

On the ends of your arms, at the stops, you'll want a tab of some sort to stop the swing and give the latch something to pull the arm up against. You could add a small plate to the bottom of the tube that hits the stop that the arm rests on, that's how mine is designed.

I assume the poly stops your referring to are what the arms rest on, not the swing stops for the open position that are near the spindle (which I don't see but you will need)? I started with a hard poly stop near the spindle and found it only lasted a few weeks. Ended up replacing it with a steel stop recently and much happier so far.

Keep up the good work, look forward to seeing this become a reality.

Thanks for the comments and ideas! I've been busy so the design stalled out a bit but I plan on working on the design this coming weekend.

 

[ScratchedFJ]

Hey Everyone,

So it's been forever since I did any design work on this. I've added some light bracing to the tow-hitch but it will need to be triangulated for stiffness. I've also quickly added some GrabCAD models of a 33" wheel/tire. I need to figure out how to brace/gusset the jerry cans. I'm liking this design as it get's most of the wheel pretty low. I may have issues with tow hitchs and towing but I have not towed anything in nearly a decade so it will more likely be used for recoveries.

 

[sxp]

Figured I'd drop some pics of my current 'in process' rear bumper for you. The frame is cut to fit it. The mounting brackets were designed to hold a 3x3 tube for easy assembly and welding. The four holes allow for a removable JK receiver, and the area is braced on the inside with 2x2 tubing. The next steps are installing 4x4Labs swing arms, custom tire carrier, shackle mounts, and small end caps. I am not going for large wings on this bumper.

 

[jcardona1]

After running two bulky bumpers with swingouts, racks, ladders, I got annoyed with the weight and low clearance so I cut the frame rails, cab mounts, chopped and capped the quarter panels, and built a high clearance bumper integrated into the body mounts. It was a lot of work for a simple look but I'm happy with the outcome. One of these days I'll paint it.