The Foreward: My Custom Winch Bumper Build

[babyeater304]

My Custom Winch Bumper Build UPDATE #1 With 50% complete pics!

So about a month ago I smacked a deer at ~40mph and it ruined my front bumper. Luckily, 95% of the damage was aesthetic, and while the vehicle is still fully functional (save for headlights that have been slightly displaced and now aim ever-so-slightly downwards from stock), it's time to replace it.

So, I figured since I am not the only one who is/will be going about building my own bumper, I am going to document everything.

THE PLAN: I wish to design and fabricate a new front bumper for my 2002 4Runner SR5. The bumper will be constructed from Sch 40 1.5" carbon steel ERW pipe (1.9" OD), bent and welded to shape in a "pre-runner" style. It will be directly connected to the frame via welding (possibly welding on a bracket for the bumper, then attaching the bumper via removable means i.e. bolts, depending on winch placement). I also plan on incorporating a winch into this project; these details are still in the works. I have considered frame-mounted 2" hitch receiver winching, bumper-mounted winch, etc. I am still on the fence, but considering I want this to be as uncomplicated as possible for my first built (and first winch, on any vehicle, ever), I am thinking of permanently attaching a winch mounting plate to the bumper so as to affix the winch to the bumper.

So, seeing as how I have already completed some of the designs, but have yet to record any digitally or upload any of my pictures, I figured I would start this thread a few days early to garner some discussion. Any discussion, questions, or (especially) input/advice from those who have done this before would be greatly appreciated. The more we all talk, the more brains get churning and the more good ideas end up floating to the surface. I plan on making all the documentation of the project, from the designs to pictures of the progress, available here at T4R so the next guy who decides to do this has a solid bed of information to pull from.

 

[techno]

ok, i'll start with a question. Why weld it to the frame?

 

[babyeater304]

ok, i'll start with a question. Why weld it to the frame?

Where else would I attach it?

The stock bumper is mounted more or less to the frame. Give me a day or so to put up some pictures of what I mean. The stock bumper is connected to the frame by bolts; the end of the frame has an endcap plate- to this plate, a frame extension is bolted/welded on (with some pretty weak weld, from what I can see). I can easily see where, if you were to put tension on the bumper (pulling with a bumper mounted winch, for example), it would easily tear the bumper's frame extension from the frame itself. I am going to forgo this, hack the endcap plate off the end of the frame and start fresh, not unlike the ARB frame end mod for ARB winch bumpers.

This is all from my observation. Am I wrong?

 

[nquaint]

when I made mine I used 90 degree steel pieces with bolt holes to mount my bumper to the same points as the stock one with the same bolts. Worked out pretty good but yeah you could be right about them ripping out if you are on the winch. I don't have a winch so I'm not worried, and it's been banged around quite a bit, no problems...

 

[techno]

My question wasn't directed at the mounting location, but rather the welding instead of bolting. Welding a mounting bracket to the frame is fine, but having the entire bumper welded in place would be a bad plan in my opinion. I would prefer the abilty to remove it if needed.

 

[brian2sun]

I agree with techno. Weld the mounts to the frame and then bolt the bumper to the mounts in case you need to remove it. That's how mine is.

 

[kaiser]

Kind of how they recommend you weld the mounts for the ARB bumper to the frame and then bolt the bumper to the mounts, if you weld the mounts it will be stronger for winching, yet still give you the convenience to just unbolt it and take it off for repairs or what not.

 

[babyeater304]

See, we are making headway already. It does make sense to weld a bracket to the frame, and bolt the bumper to the bracket for reasons stated above. Seeing as how I have yet to come up with a plan for mounting, lets discuss this further. I was thinking taking the recovery hooks off the bottom of the frame and starting there. Reason being, on the outside inside of the frame you are afforded only about 2" of free space before you hit the radiator crossmember, and on the exterior of the frame you only have 2.5" before you run into the support bracket for the crossmember. So, welding the brackets to the bottom of the frame. Good idea? Bad idea?

 

[brian2sun]

The ARB mounts completely slip over that 2.5" exposed section of the frame rails (it's just a bigger rectangle that slides over the frame), then they have a long piece on the bottom side which extends out and lines up with the holes for the tow hooks. This way the mounts can be bolted on too. Mine are bolted like that, but then I welded them to the frame also for added winching/pulling strength. Then the actual bumper is just bolted to the mounts with 6 grade-8 bolts.

 

[babyeater304]

Update #1 - 09 August

So some reconstructive knee surgery and two summer jobs have hampered my updating progress, but only slightly slowed my fab progress. So here I present,

THE BUMPER.

So I basically worked on this in the fab shop of a company I worked at for a few months this summer. The late office hours afforded me about an hour a day to use all the equipment in the facility (several hundred thousand sq. ft), when I didn't have my night job to get to.

So here's basically what I went with. I used 2x.25" sq tubing to create the sub-frame and welded it (tacked for now) to the actual truck frame, all the way back.

From that, I squared it off in the front and added one support beam as far back as possible (right up against the radiator support bracket thing). I then created the brackets to mount the tube out of .25" and tack welded them onto the sub frame. I am in the tediously slow process right now of drilling out the bolt holes so I can break the tacks and use bolts to connect the tube portion of the bumper (via 2x .5" grade 6 bolts per side). The plan is to use the bolts to compress the bracket on to the frame so that under normal loading, the friction between the bracket and subframe will bear the load and not the bolts (which would be in double shear. grade 6 @ 120kpsi ultimate tensile, take roughly 50% of that for shear @ safety factor of over 2 and you get 60kpsi ultimate shear, take that * 4 bolts * cross sectional area * 2 due to double shear to get a max loading on the bolts of ~ 23.5 kip, or at least 3x weight of the vehicle. and that's AFTER the frictional loading fails)

So anyways, I gave it a prerunner-style stinger on the nose, and one length of protection around the front ends that tie back under the front fender. I had originally planned on tying the ends of the bumpers back to the base of the bumper for added rigidity, but simply ran out of time. It is something I am not concerned about right now, as the 1.5" sch40 pipe is extremely rigid as is, but I will add later on when I get some time up at school.

^^^ This is my one concern right now. That thing I built sticks way out there, and I am concerned right now about diminishing approach angle. I originally measured to leave enough room for a winch to bolt down to the subframe in the front (right in front of the radiator). I may have given myself TOO MUCH space. The winch addition will be soon; right now I am contemplating what to do. I know I want to add a winch here soon (more like eventually), so what I am thinking about now is ordering the winch I want, probably the biggest one from harbor freight (as it will be my first winch on my first truck and I want to learn on the cheap, plus I hear they are 99% identical to Ramsey and quite good for the money), then re-constructing the front of the subframe so that I have enough room to put the winch but not an unnecessary amount that will hurt my approach angle.

Anyways I will get more pictures up soon, I have a lunch date I must leave for. Any questions/requests?

 

[brian2sun]

Your approach angle is definitely going to suffer like that. You'll need to modify it once you get the winch like you were thinking if you plan on off roading it much. Check out Smittybuilt's 8000 lb. winch, they're still pretty cheap ~$299, but a lot better than Harbor Freight. Bumper looks cool!

 

[jsmarine]

Your approach angle is definitely going to suffer like that. You'll need to modify it once you get the winch like you were thinking if you plan on off roading it much. Check out Smittybuilt's 8000 lb. winch, they're still pretty cheap ~$299, but a lot better than Harbor Freight. Bumper looks cool!

X2 on the smittybilt, that's what I have.

Also, check out Manhunter's bumper, he did a tube bumper like what you are doing. 1st thread http://www.toyota-4runner.org/3rd-gen-t4rs/61387-manhunters-front-bumper.html 2nd thread http://www.toyota-4runner.org/3rd-gen-t4rs/62333-manhunters-finished-bumper.html

And you can also look at my bumper build; http://www.toyota-4runner.org/3rd-gen-t4rs/63227-jsmarines-custom-winch-bumper.html I started with the winch first and built the bumper around that. Look at my early stages (same with Manhunters) and I'm sure you could get some ideas and probably still do a tubular style bumper around the winch mount.