How is your custom rear bumper mounted to the frame?

[hammer]

Hey Guys,

I'm re-working my rear swing out bumper mounts to make it better for towing my tent trailer. This is what I have now;

So I picked up 2' of 2"x4" - 1/4" thick steel to make new mounts. Idea is go deeper into the frame and tie into more than just the frame horns. Having a bit of trouble wrapping my head around the best way to do that. Here's how deep I can go into the frame without modifying the tube.

I have a hole already drilled in the top of the frame that I use to attach a custom mount for my 23 gallon tank. Not sure how I'd get a bolt attached at that point though. Kinda hard to weld a nut inside the tube. Guess I could go right through but from what I've read that's not ideal either.

I can cut and angle the tube like below and maybe go a half inch further into the frame before I hit the body mount;

My other option that i've thought of is boxing in the frame horn area and mounting horizontal through there;

Here's a link to my original brainstorming;

http://classicbroncos.com/forums/showthread.php?t=203630

I will be cutting off the reciever and mounting a new one that will be recessed 1.5" into the bottom of the bumper and triangulated. Here is the drop ball mount that I built to replace the store bought adjustable one. This will allow the tent trailer to ride exactly level;

Any advise on the mounts?

 

[firehawk]

I boxed mine in and still need to mount my rear bumper, might have to make some brackets.

 

[asinor]

This is one Mad posted on my bumper bolt thread.

Bolt in from the sides, bypass the body mount and the bump in the frame tubing.

 

[KyleQ]

My setup looks lame, but I wouldn't hesitate to hang the truck off the rear pull point.



I fully welded that tubing to the frame and left the grade 8 bolts in it-

I know that doesn't help you - why not build a receiver style mount with plate off the frame to a central bar. It wouldn't have to hang down at all, just the thickness of the cross bar.

 

[hammer]

Good stuff guys, getting the juices flowing here. This is my new idea;

 

[Greg_B]

I dont have a photo of it and I have not finished installing it yet but I made a plate with two 1/2" bolts welded to it and slide it into the bottom of the frame rail. I drilled one hole on each side and one hole already existed for the bolts to stick out of.

I then made two angled pieces to bolt to those and they wrap around the frame and up to the open area shown in your photo/ I then ran two 1/2" bolts through the angle and through the tube inserted in the frame rails.

Clear as mud? When I finally get them installed I will take photos. As it sits right now I just have the same 4 bolts that everyone else uses.

I made a reciever hitch that mounted like this many years ago and it was very strong. So I tried to do the same thing with my bumper. I would pull a light trailer just like it is now though.

Greg

 

[KyleQ]

Here is my front bumper - no direct pics (yet) but it is very tough and simple.



I basically bolted 1/4" angle iron to the frame so the angles point inwards and I had a nice flat surface to weld to that was flush with the frame rails. I then welded on the tubing you see after I added a receiver tube in the middle. The bumper basically is held on by four grade 8 bolts and is very stout.

 

[00gyrhed]

your second photo is pretty much what I did, which is really more than you need. I used a heavy channel and bolted it to one side with two bolts and top amd bottom with one each. It aint going anywhere.

 

[hammer]

If I do what I have drawn in post #5 do you think that i could just drill and tap the 2x4 and bolt it in? Its 1/4" wall.

like this?;

 

[xcntrk]

I don't mean to sound like the naive one here, but can't you just leave the current vertical nut/bolt through the horns, then run a sandwiched set of steel plates inside and outside, between your bumper mount and the inner box frame beyond the horns? Then run a pair of horizontal nuts/bolts through both ends? You could even leave your existing setup as-is and still do this. Lots of extra support for minimal effort.

 

[asinor]

Once you have it to the shape you want, put it in, bolt with existing bolt, drill new holes, take it all out, weld nuts where you want them.

 

[hammer]

I don't mean to sound like the naive one here, but can't you just leave the current vertical nut/bolt through the horns, then run a sandwiched set of steel plates inside and outside, between your bumper mount and the inner box frame beyond the horns? Then run a pair of horizontal nuts/bolts through both ends? You could even leave your existing setup as-is and still do this. Lots of extra support for minimal effort.

In theory yes, but there is basically no room on the inside of the frame with a 23 gal tank. There is no way I could run a plate in there and bolt it up.

And I've already cut the old mounts off the bumper today. Past the point of no return.

 

[hammer]

Once you have it to the shape you want, put it in, bolt with existing bolt, drill new holes, take it all out, weld nuts where you want them.

Yeah that's the plan. I just don't think i will able to weld a nut inside the tube. How would I get in there to weld it? The only one i would have access to weld would be the one farthest back That i outlined in the pic in post #9.

 

[deltarat]

Welded a piece of 1 1/2 x 1/4 on the top and bottom to strengthen the holes.

 

[hammer]

Welded a piece of 1 1/2 x 1/4 on the top and bottom to strengthen the holes.

Good call, was thinking of welding washers around each one, more so just to strengthen the holes at the horns.

 

[Doyle]

Good call, was thinking of welding washers around each one, more so just to strengthen the holes at the horns.

Why not put the 1/4" flat stock inside the tube, top and bottom, and weld what you can reach? Will give you twice the material to tap. Washers sound like a good idea on the frame horns.

 

[00gyrhed]

I welded nuts to the backside of mine. Just make sure everything cools down completely before you take them apart the first time. But then again I used a heavy channel so that was easy.

 

[00gyrhed]

pictures of mine

some are from front build because I didn't have similar pics of the back.

I meant to do a better job of documenting everything I did, but the further away from it I get I realize how much I did without pictures. I have a 4" binder full of the non stock stuff I did and thousands of pictures but the pictures have a lot of holes in them.

 

[Steve83]

How far rearward of the frame do you plan to run that tube? If it's not far, then cut it & weld the rearmost nuts in from the back. If it is far, holesaw the sides so you can weld the nuts in. Or holesaw straight thru vertically, drop in a thick-walled round tube that you can weld to the rectangular tube from outside, and then tap the vertical pipe.

 

[jms5580]

For my front bumper I cut and ground 2x4 until I got it as far in as it would go, maybe about 4", then drilled 2 holes horizontally through each side and bolted with grade 8. The plate on the bumper, in addition to whatever it's butted up against on the inside, prevents it from moving (on top of the bolts). I have no doubt that the bumper can withstand more than the frame could at this point.