Everyone knows that a nice and convenient way to remove your box-body bumpers is to put a 15mm socket on the big bolts that hold the bumper-shock mounts inside the framerails, and remove the bumper and mounts all as a unit. But sometimes the mounts have been inside the framerails for so long, or under such wet and salty conditions, that they're rusted in place. When you use a tow strap to tie the end of the bumper to a stationary object, and move the stationary object while the bumper mount stays rusted in place, you're pretty sure it's time for another approach.
No biggie, you think, so you go to remove the nuts (or sometimes bolts) that hold the bumper to the mounts - and guess what? On one side, only one the nuts will come off. One stud shears off, and the third one ends up getting cut off. This isn't all bad, since you've got your bumper off, but you're also left with a bumper you can't conveniently reinstall.
This brings us to my garage yesterday, when I pulled apart a bumper removed under precisely the circumstances described, to arrange things so it can be reinstalled. The one I was working on used studs, but approach for the nut-bracket style would be similar. In this case, since the original flat L-bracket-with-studs-attached from one side was basically garbage and not easily repairable, I decided to make a new one instead and headed out to see my local Helpful Hardware Man.
Since I didn't find a premade bracket of the right size, I bought a strip of weldable steel, 1/8" x 1" x 3', for $6.99. Lowe's would probably have been a little cheaper, but I wasn't at Lowe's. Class 8.8 M10x1.50 bolts were likewise pricey at $1.39 each ... pretty sure the ones I got were 45mm long, but you'll be taking a sample bracket to your hardware store for reference anyway. My thinking was that I'd save a little trouble by keeping the stock threading, but if I'd gotten SAE I would have avoided another difficulty later ...
The first step was obviously to cut the steel strip into appropriate lengths and weld it together. The third pic skipped a step and shows it after some halfhearted cleanup and after I drilled and tapped holes for my new studs. I didn't worry too much about appearance, because no one's ever going to see this! I ended up running a tap through the holes mainly because I couldn't locate my larger drill bits, but it turned out conveniently because it also meant I didn't have to hold the bolts in place while welding. And if you were to use brass instead, the brass would run into the threads and be very strong.
Pics 4-5: Ran the bolts into the new bolt holes. A couple stripped somewhat, but that's not a big deal.
Pics 6-7: After welding. I keep forgetting that steel that's just been heated near its melting point is HOT!
Pics 8-9: After some cleaning and painting.
So that's basically it. I used a flux-core wirefeed welder because it's easy and I had one handy, but you could braze it together just as easily ... like I mentioned, it might actually be a bit stronger because the brass would run into the bolt threads instead of melting them, and the shear strength of brazing is supposed to be very high. You could also cut the bracket out of a piece of 1/8" sheet stock and use slightly longer bolts retained with jam nuts, and eliminate the need for welding processes altogether.
So far so good. My current hangup is obtaining a handful of the little retaining washers that actually hold the stud brackets inside the bumper core - otherwise they'll fall down inside the bumper when you go to install it, which might prove mildly annoying. Ace had this sort of washer for like 75 cents each, but only in SAE, which is why I mentioned it'd have saved some slight trouble if I'd gone SAE on the studs. I'm sure Fastenal or McMaster-Carr have them in M10, but I'll be having to spend some more quality time with the online catalogs or else go into the Fastenal store and ask an actual person for help.
It's also occurred to me that I could take regular washers and zap a tack weld to hold them on, but I'd have to exercise caution because the bumper core I'm working on in this case is itself steel, and it'd defeat the purpose of the design of the thing if the studs didn't move with respect to the bumper.
No biggie, you think, so you go to remove the nuts (or sometimes bolts) that hold the bumper to the mounts - and guess what? On one side, only one the nuts will come off. One stud shears off, and the third one ends up getting cut off. This isn't all bad, since you've got your bumper off, but you're also left with a bumper you can't conveniently reinstall.
This brings us to my garage yesterday, when I pulled apart a bumper removed under precisely the circumstances described, to arrange things so it can be reinstalled. The one I was working on used studs, but approach for the nut-bracket style would be similar. In this case, since the original flat L-bracket-with-studs-attached from one side was basically garbage and not easily repairable, I decided to make a new one instead and headed out to see my local Helpful Hardware Man.
Since I didn't find a premade bracket of the right size, I bought a strip of weldable steel, 1/8" x 1" x 3', for $6.99. Lowe's would probably have been a little cheaper, but I wasn't at Lowe's. Class 8.8 M10x1.50 bolts were likewise pricey at $1.39 each ... pretty sure the ones I got were 45mm long, but you'll be taking a sample bracket to your hardware store for reference anyway. My thinking was that I'd save a little trouble by keeping the stock threading, but if I'd gotten SAE I would have avoided another difficulty later ...
The first step was obviously to cut the steel strip into appropriate lengths and weld it together. The third pic skipped a step and shows it after some halfhearted cleanup and after I drilled and tapped holes for my new studs. I didn't worry too much about appearance, because no one's ever going to see this! I ended up running a tap through the holes mainly because I couldn't locate my larger drill bits, but it turned out conveniently because it also meant I didn't have to hold the bolts in place while welding. And if you were to use brass instead, the brass would run into the threads and be very strong.
Pics 4-5: Ran the bolts into the new bolt holes. A couple stripped somewhat, but that's not a big deal.
Pics 6-7: After welding. I keep forgetting that steel that's just been heated near its melting point is HOT!
Pics 8-9: After some cleaning and painting.
So that's basically it. I used a flux-core wirefeed welder because it's easy and I had one handy, but you could braze it together just as easily ... like I mentioned, it might actually be a bit stronger because the brass would run into the bolt threads instead of melting them, and the shear strength of brazing is supposed to be very high. You could also cut the bracket out of a piece of 1/8" sheet stock and use slightly longer bolts retained with jam nuts, and eliminate the need for welding processes altogether.
So far so good. My current hangup is obtaining a handful of the little retaining washers that actually hold the stud brackets inside the bumper core - otherwise they'll fall down inside the bumper when you go to install it, which might prove mildly annoying. Ace had this sort of washer for like 75 cents each, but only in SAE, which is why I mentioned it'd have saved some slight trouble if I'd gone SAE on the studs. I'm sure Fastenal or McMaster-Carr have them in M10, but I'll be having to spend some more quality time with the online catalogs or else go into the Fastenal store and ask an actual person for help.
It's also occurred to me that I could take regular washers and zap a tack weld to hold them on, but I'd have to exercise caution because the bumper core I'm working on in this case is itself steel, and it'd defeat the purpose of the design of the thing if the studs didn't move with respect to the bumper.
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