The die is cast: DIY weld rear bumper and tire carrier (True North Fabricatiions)

[Kryptoroxx]

I would say you could easily weld some metal mudflap frames away from the tire that wouldn't take long to remove the flap on.

Look in the trailer section of a local farm store (not sure if those are close by or not) and you could find a metal license plate frame. Easily welded on so you don't have to do anything further or try and drill the bumper. I'm sure Cramazon might have some offerings as well and there is always zip ties! lol

[Bob98SR5]

I'll check out the trailer section out, thanks for the tip. But now you've probably made my choices more difficult. I betcha Tractor Supply has the back to back chrome buxom ladies facing each other. My mind was almost set on the Yosemite Sam "Back Off" flaps lol.

I did do some homework late last night and I saw that a few people cut up some rectangular mud flaps for big rigs with all kinds of different ways to ake sure the flaps don't hit the tire, usually with a wire of some type.

Oh so here's the CA law. In short, there's a requirement for both width and height/length of the flap...sorta:

Code 27600 of the CVC states, "No person shall operate any motor vehicle having three or more wheels, any trailer, or semitrailer unless equipped with fenders, covers, or devices, including flaps or splash aprons, or unless the body of the vehicle or attachments thereto afford adequate protection to effectively minimize the spray or splash of water or mud to the rear of the vehicle and all such equipment or such body or attachments thereto shall be at least as wide as the tire tread."

Height:
Law 27600 CVC does not give any specifics on mud flap height requirements, other than saying that they must provide sufficient coverage to block anything rotating tires can kick up. If you drive a raised vehicle, you are still required to have mud flaps that are low enough to the ground to stay in compliance with the law.

So the stock flaps are 6.5 inches tall and 9 inches wide as measured from the top of the flap part (where it meets the bottom part of the bumper). So since my lift is about 2", then I'll need to account for the lift AND also for the decreased height of the new bumper. The new bumper though has very little material horizontally to support the flap, so I may need to make a custom flap hanger (bolt on) to make this happen. I've attached two pics of what I'm thinking and the diagram showing how little material I have to work with.

[Bob98SR5]

Well I decided to remove the bumper after the test fit to do welding the nuts that secure the future tire carrier to the bumper. This step is advise prior to welding all the seams as according to TNF, the metal gets harder after welding. So I decided to do both sides as I'm still undecided which side to mount the carrier.

However I thought I could save some time and use jack stands and lower the bumper. What a mistake. The right side (passenger) got hung up on the exhaust pipe and the driver's side wing jerked towards the passenger side and moved backwards at the same time. I heard that metal on metal scrape and I just cringed. I got out from underneath very carefully and saw a 2" gashy gashy >

The other side got a little bit too but not as bad. I got wise and put some microfiber towels in between the body and the bumper. I kicked the exhaust pipe out of the way like the mad Korean ninja that I am and it all came loose.

Some other things:
- Yes, there's NO way you can mount the spare underneath. Not by a mile. So time to weld in those diagonal braces tomorrow.
- I took a stab at practicing my welding skills. Oh boy, I need to improve my welding game stat!
- I am so bad at welding vertically

I heavily tacked in the nuts on the back of the rear bumper ends per instructions. I was planning to put the bumper back on and call it a day, but I had 2 hours so I did some additional welding. Not everything turned out perfectly.

Advice sought: as you can see in the pics, there's some small holes and some gaps in between weld start and stop points. For the bigger gaps, I'm going to fill it in with the welder and regrind/flap, but for the smaller ones, can you just put bondo in it and call it a day and sand? I'm trying to minimize the welding and flap disc time.

[4x4mike]

Structurally you'll want to make sure there is enough weld in the gaps to hold everything together. The bumper acts as the bridge to your frame which will support the tire as well as recoveries. One thing I wouldn't want to have to chase down are little cracks caused by the rear tire carrier. Burn it in good then grind down. If there are small pits you could use bondo but make sure you've got enough weld.

Are you welding from both sides? Or do the instructions specify for a given section? "Provide sufficient coverage to block anything rotating tires can kick up" I feel speed and substrate have a lot to do with this. In some instances a short flap could do the job.

Bumpers looking good there Mr. Korean Ninja.

As for the mud flaps, it's good that you looked it up. I thought part of the rule was that the flap had to cover at least half of the tire. Like it couldn't be too short. Say the OD of your tire was 33", I though the top 16.5" had to be covered.

[Bob98SR5]

Mike,

Good advice, thank you. The instructions are pretty specific on where to weld (inside or out) and where to grind or not grind. The vast majority of welding is done on both sides.

Thanks for the answer on the bondo. I think I'm going to bondo then. I just didn't know if it was possible or not. There's a few places where its just a teeny tiny hole and to add a tack and then flap would be just overkill for the effort.

Re: flap length, I compared what I read to pics of the stock 4runner plastic mud guards. All of them end about the center of the hub, so that's the length I'll cut it down to. I bought this on Amazon. I opted to buy the thicker rubber kind vs the cheaper plastic kind, which many people said is akin to the flexible plastic cutting board material you can buy at IKEA for like $4.99. I'll definitely need to cut it down. Thinking out loud, I'm gonna weld some nuts on the other side of that triangular piece of metal at the end of the bumper wings in 3 places as mounting points so I can hang the mud flap off of. At least that's the plan for now.

[Bob98SR5]

After welding in the little odd shaped triangular piece (Fabrication step 11), it was onto the flaps.

I had to do something REAL quick tonight to get flaps on the new but unfinished bumper before we hit the road south this weekend for one of Casey's shows. Hit Ace after work, got a 12 gauge 1" flat metal bar and decided to bolt it into the bumper as I want to be able to remove it later to make something more professional. I bought some ¼" self drilling screws to mount through the bumper and then some regular nut, bolt, washer, and lock washers to secure the side that extends into the body cavity.

I ended up cutting the flap 12" long and 10" wide. 13" would've been a little below the center of the hub, but 13 is an unlucky number. Now I scoff at superstitious hokus pokus bulls@#t, but this one and the number 4 are ones that I do have some belief in as unlucky numbers.

Getting late, so here's the pics of how I first tapped the holes 1/16th smaller than ¼" for the self tapping screws and the other 2 holes for the nut/bolt combo that secures the rubber mud flap to the metal bar.

My only concern at this point is if the looseness of the flaps with slap incessantly against the bumper. I know that some flaps have a wire that attaches to the end of the flap to the bumper, so that might be an option of this doesn't work.

I ended up spraying it with some satin black just to give it a head start as it'll turn black from road grime soon enough!

Edit: I didn't weld in Step 12 in order, but here's a shot of what that little piece looks like. Of note when I welded it in, the paint didnt bubble up and fall off at all. I ended up primering and using the bed liner paint. Looked just fine.

[Bob98SR5]

Last weekend was spent down in LA for my wife's jewelry show so no work on the bumper. Surface rust is developing where the water has hit the bumper, so I got to get moving on this as I don't want to rust abate or spend needless time de-rusting before priming and painting.

I'm at the point where I can start welding the tire carrier. The kit by default is for passenger side swing out and there's no instructions on how to flip it to the other side. So I decided to re-examine the pdf instructions and all the parts in the first few pages of the instructions can be flipped to mount the carrier on the driver's side up until one step and part. It's the part that the horizontal pipe of the tire carrier passes through and is part of the latching mechanism. The part as you can see in the pic has only one entry hole for the pipe to pass from the passenger side towards the driver's side (right to left). To mount it from the other way around, a hole needs to be cut in this part to allow the horizontal pipe to pass through it.

So with two $5 off $20 purchase Ace coupons in hand, I went to my fave Ace Hardware store and bought a 1-¾" bi-metal hole saw and the special part that drills the center hole and holds the hole saw (can't remember the name of this part). The hardest part was to center and clamp down the part to my drill press. I lined it up just about perfectly and clamped things down. It took a bit of fanagling, but worked well enough to drill a mirror copy of the hole (which is a bit off set).

That's all the time I had for today (tons of morning errands and my tired ass took a nice 2 hour uninterrupted afternoon nap), but tomorrow will be devoted to tack welding the rear tire carrier, fully welding the bumper per instructions, and flap disc'ing to make it purdy.

Pro tips: do not apply too much force down in the very beginning. Make sure the drill bit centers well and that's 90% of drilling a hole through metal perfectly. Also make sure you use tapping fluid to cool down the bit. Finally, don't rush and burn the hole saw or the centering bit.

Idiot move: since I was in a rush, I wasn't thinking and didn't put the part on a piece of sacrificial wood. Stupid me gouged my drill press platform.

[Seanz0rz]

Evaporust will do wonders if you cannot get to the rust in time. HIGHLY recommended! you would probably want to use the gel stuff since you cannot submerge the part in fluid.

Looking great! I've been busy with mine, thread to come soon.

[Bob98SR5]

Thanks for yet another recommendation, Sean. Oh by the way, do you have a recommendation on a spray to shoot down the tubing? I know what water can do to the inside of metal, so rather than drilling drain holes, I'd rather spray a chemical inside.

[Bob98SR5]

So today was the start of the tire carrier per instructions up to Step 7.

As I had the full day to work on my bumper after a 10am haircut, I set out all the parts and started working through each step. But this set of parts unlike the rear bumper had a lot of flash that needed to be wheeled off w/ a Dremel. The hinge bracket was 3 pieces that needed to be set at right angles to each other and was pretty easy to tack.

Next step was to tack weld the hinge stops part to the DOM vert tube. After doing that (it was slightly off but barely), I ground down the high spot and test fitted it with the DOM vert tube and parts inside the bracket. I tell you, this thing fit in so perfectly that I had one of those 'whoa' moments. After fitment, the next step called to tack weld the T-handled plunger to the top of the mount.