Nakedginger

Thanks, I've been putting alot of work and thought into this. While I was at it, I also put TJ rear fender flares in place of the stock XJ flares up front. It opened up the wheel wells a bit so the tires can move around.

Nakedginger

Alright I finally have the bumper welded to the mounts. Here's how she looks! Its just the base for now so soon Ill start working on the stinger and the mounting system for it. Its MUCH more solid then the other bumper was. Ive already used the hitch in the front for recovery. Works like a charm

jeepsurfer1

You welded it to the "frame" ?

Nakedginger

No, sorry I wasn't clear. For mounting the bumper, on both sides I took 1/4" angle iron and cut two pieces to the width of the frame. I had already put frame stiffeners in so I then welded one of the two 1/4" angle iron pieces onto the outer surface of the frame and the other angle iron to the bumper. Then to attach the two angle iron pieces I drilled holes in the two faces pointing twords each other, and put two 1/2" grade 8 bolts in it. I did this to the other side as well. there is a picture earlier in this build thread showing the orientation of all four angle iron pieces. so yes, on the drivers side and passengers side there is a welded angle iron to the frame which then lines up with a corresponding angle iron on the bumper and are bolted together holding the bumper onto my XJ.

Nakedginger

As the title says, slow build. I finally made time to get back to this build. After playing a bit, I created the plates that the brush guard piping will attach to. These then will be bolted to the tabs mounted to my front bumper. The first picture is of the template and the second the mostly completed tabs.

Nakedginger

I finally got some more free time and decided to tackle this project once again. The main frame of this build was completed when the bumper was finished. Now its time to make the tow bar/stinger. I stared by purchasing a pintle drawbar and shaping it to be only a ring. To do this I used a porta band and a hand held grinder.







It didnt come out perfect, but I decided to weld one of the tubes where I had cut the drawbar. I then moved on to find how high the stinger was going to be as well as the length of each side tube. To find this I went over to the 82' Chevy Blazer my dad has and measured from the hitch out to the end of its side. This measurement informed me how long the side dimension of the stinger needed to be. I figure if I make the tow bar fit the dimensions of my dads Blazer, it will be set up for most rigs out there today. Its a wide Chevy. This length accounts for the measurement of the drop tube and about two inches of the drawbar. I added the two inches of the drawbar because its a measurement from the pintle to the mounting point. Since the pintle is inside the drawbar, I threw in that distance. With this length and geometry, I found my dimensions and started making a template.



The dimensions ended up being 33 inches for the drop tube plus the drawbar and the overall height will be about 31 inches tall. At what angle from the body, I am not sure yet.

Lowrange2

Here I am being the bearer of bad news again. Sorry.

So, You're going to flat tow a vehicle with no fail-safe brakes by a bumper that's held on with 4 half inch bolts in single shear? You do realize that's an extremely terrible idea, right?

Dan91

Well, really his bolts are under tensile load if I understand his description right (check his pic on page 2). In any case it would be plenty considering the strength of a half inch bolt, flat towing doesn't have huge dynamic loading like off-road recovery does. Tons of towbar setups rely on four bolts ran through a stock bumper.

Nakedginger

You've got it! There are four half inch grade 8 bolts holding the bumper onto the angle iron that is welded to the frame. On top of that, there are half inch grade 8 bolts holding the angle iron onto the frame along with the welds. There is my fail safe and why I placed them there.

Each bolt has a tensile strength of about 21,000 lb. More than enough to lift the XJ. Pulling the XJ behind another vehicle creates much less force than the actual weight of the truck. Most of what you are really pulling is a force greater than the friction force caused by moving parts such as bearings or gears, forces from different accelerations between the two vehicles, and some of the dead weight if on a hill. Thus the bumper should hold.

thank you for your concern. It has made me go through my design again with a critiquing view.

Lowrange2

I see now that they're in a different orientation than I had previously thought but, IMO, that's not enough.

I wouldn't consider flat towing with a tow bar unless that thing was ON there.

There's a huge difference between pulling your bumper off while be pulled down a trail at 3 mph and pulling your bumper off with no one in the Jeep at 60mph on the highway.

I just don't think it's a good idea, but that's just me.

Do what you do.

Nakedginger

May I ask you what you would consider, "ON there" looks like? Would it be more bolts? or welds? or would you want to see more safety measures taken in the situation where a bolt may snap?

Lowrange2

I would use 1/4" brackets that use all 7 bolt holes on both sides, grade 8 hardware, and the tabs that the 'tow bar' hooks to would be part of that 1/4" bracket. The tab would be 3/4-1" thick and there would be some really heavy duty safety chains from the front of the Jeep to the back of the truck towing it.

Break-away brakes would be great too but I don't know of an easy way to do that.

There's no way I'd trust a couple welds and 4 bolts to hold a 3k pound chunk of steel behind a vehicle at highway speeds. Way too much liability there.

Peewee

I think 4 1/2" grade 8's will be ok but as always more is better. Im going to point out that your hitch is held in by only one 5/8" pin, 4 1/2" bolts are 2" combined thickness which is as big as the tow ball itself. I've made several tow bars. For safty reasons i attach a chain to a seperate ataichment point from the tow bar to ensure that even if something going retarded what im towing will still have to stop with me.

Lowrange2

The bolts aren't really the issue as much as the platform it's all attached to. If you were bolting/weld a bumper to 1/4" thick frame rail then it wouldn't be an issue. The load needs to be spread out as much as possible on a thing little unibody.