Broken bumper bracket bolts in RS frame rail

[abrahamfh]

How do I remove these broken bumper bracket bolts that are stuck in the RS frame rail. Last thing I have to do to Fred forward of the firewall (other than of course cleaning the area up and hitting it up with some primer).

[mustangstofear]

I take a cutoff wheel and cut the top and both sides, then heat the bottom with a torch and bend it down, then heat the bolt and remove it. Then i will weld new nuts on the back side heat the panel back up and bend it back in place and weld it back up again. Rich.

[midpack]

Might try drilling and chasing the threads first... that's what I did and it worked pretty good

[napaguy]

If theres enough of a nub sticking out then I would try to weld a nut to it and attempt to spin it out...if that didnt work then I would drill it out and retap it.

[stangg]

If you go with the welded nut method, you might want to first soak the bolt with pb blaster for a few days,  then clean it good before welding the nut on.  Get a lot of weld inside the nut so that the heat carries into the threaded portion,  and be prepared to immediately un bolt it while it is still hot.    I like all three options in reverse order but I'll bet Rich has done it enough times to just not bother with the other issue you might be faced with...

[mustangstofear]

What I have always found is the cage nut on the back will break before the bolt will come out, that's why I always weld a new nut on the back. Once the repair is done it can't be detected. Rich.

[monkeystash]

The weld-a-nut trick didn't work for me.  It just broke off again, further inside:



Drilled out and re-tapped:



One hole, the whole dang internal nut came out, whoops!




All done on one side:

[abrahamfh]

Thank you everyone for the different suggestions in techniques.

So far, just like Ryan, the weld a nut route didn't work.

I figure I would drill out the broken bolt. So far, not looking to good. I think the internal bracket that holds the nut might be broke. It wiggled a little. Not sure if that means it's broke.

Only had enough time to drill out one hole before it got too cold.



Not sure what the next step is from here. Started with a small bit and worked my way up to bigger ones, but now I'm not sure what to do that I'm getting closer to the threads. (so I think)

[Midlife]

I think it may be time for you to consider replacing the frame rails with repro's.  With that much rust, the structural integrity of the rails is IMHO questionable.  I had to replace one on Midlife.

[abrahamfh]

The areas on the frame rail that I hit with the wire wheel cleaned up to smooth shiny metal but I did look up the cost of the repo outer portion of the frame rail and it isn't that bad.

[Ponyman66]

I just opened my frame rails up Monday to repair this very problem (no pics because there's not a lot to see!). Three of the four nuts were so corroded they just broke and dropped down inside. I'd had problems in the past with getting the bolts out on previous cars, but had never had them just disappear. As such, I had never seen what they looked like inside the frame rail, assuming they were just a captured nut pressed into a depression.

While the right side was completely gone, what remained in the left one was interesting. The nuts are pressed into a structure. The surprise came when I discovered this structure is actually a 16ga box, for lack of a better description, with the nuts pressed in. The box is slid inside the rail and then spot welded in several places to keep the nuts aligned with the holes. In the picture that Ryan posted showing the nut, you can see the flange where it was pressed into the box. The picture he posted where you can see a hex shaped hole looking into the round frame rail hole is the box structure. You don't see this when everything is okay because the pressed nut just looks round and recessed. That's also why if anyone has ever had a bolt that just keep spinning (because it didn't break off first), it means you actually rounded out the hex shaped hole in the box structure or the nut itself!

If you can bring yourself to do it, I'd suggest taking the plunge and cutting open a section on the inside of the frame rail to allow access. Once you get everything out (it'll be pretty clear what you need to do once you see inside), weld some flanged nuts to the outside frame rail, centered in the holes. I suggest flanged nuts because they give more area to weld. Once done, just tack the removed sections back into place, weld them up and grind the welds flush. You'll never know they were opened once painted. The frame rail structure is made of 16ga steel, so it's pretty forgiving when it comes to welding. It took me about 45 minutes total to do both sides, plus another 5 per weld to dress them up.

Abe you should have enough welding time under your belt now that it should be pretty easy for you and you'll be proud of the results. Unless you really crank the heck out of the voltage, you shouldn't have any problems with burn through. Try to drill them out first, though IMHO it's a coin toss as to which would be more productive versus effort spent.

BTW, The rear bolt is located pretty close to the mounting bracket for the sway bar brackets. You won't be able to open up the frame rail to allow 360deg access around the rear nut for welding. You CAN get it close enough to allow welding about 90% of the way around it though.

Good luck with whatever you decide!

[abrahamfh]

Here are my options to reach the internals and repair the bumper bracket bolts yada yada.

Option A, cut the outer piece of the frame rail, remove the internals and weld in the patch.



Option B, cut the inner piece of the frame rail, remove the internals, weld flange nuts to the outer frame rail and then weld in the piece that I cut out.

[stangg]

Access and structural wise, option A seems way better to me.   With option A you can remover the outer cover and work it on a bench and then re install as an assembly.

[monkeystash]

How about option C, Rich's way?  Seems the easiest and least intrusive.

I take a cutoff wheel and cut the top and both sides, then heat the bottom with a torch and bend it down, then heat the bolt and remove it. Then i will weld new nuts on the back side heat the panel back up and bend it back in place and weld it back up again. Rich.

[napaguy]

I think it may be time for you to consider replacing the frame rails with repro's.  With that much rust, the structural integrity of the rails is IMHO questionable.  I had to replace one on Midlife.

????? Your kidding right?

[67FSTBKRestoMod]

how bout just drilling some 1 inch or so holes on the other side and use nuts like such

new repop rails (one piece) come with these holes (yes they still have the "nut plate" inside them)

[jtfx6552]

I'd be surprised if there isn't a lot of hidden rust and damage in that frame rail. I'd take a minimalist approach to getting it open enough to see what is going on in there, but I think you'll find you'll want to replace both the inner and out once you see inside.

[Ponyman66]

Abe, the method I used is what you have labeled as option B. You have nice flat surfaces on the top and side to reference for leveling the piece back in. They're helpful too as a reference point when finish grinding the welds. The biggest thing you have to account for is the thickness of material your chosen cutting device removed, and space the removed piece back in the hole accordingly. I found the cut off disks at Harbor Freight are reasonably thin and are readily available. There are thinner disks available though a body saw is great because it makes a VERY thin line, but it can struggle a little with thicker gauge metal (dependent in part due to air pressure available for the saw, quality of the saw blades and quality of the tool).

I'm certainly not saying my chosen method is any better, or any worse that the others offered. Each has it's benefits and pitfalls. Just remember, any cutting, bending, reshaping you'll be doing is in 16ga. It doesn't move around as easily as 18 or 20 ga! Due to the sun setting when I get home from work I won't be able to do it until Sunday (my next day off), but I'll shoot a pic then and post it of my finished repair for you.

p.s. To space my removed section for welding, I just inserted a cut off disk into the lower cut. This raised it back close to the original height. I then moved it a little by hand to completely level before tacking. Once it was all tacked level, I just welded the piece fully.

[mustangstofear]

By looking at your pictures your frame rails look fine. You could drill a hole on the inside but I doubt you will have enough room to try and weld a nut in there, Ford figured it was a problem and started making a large access hole on the inside in 67. Rich.

[Midlife]

????? Your kidding right?

Why would I be kidding?  The steel on all four sides was rusted through in places and it was easier to replace the front frame rail than to patch it.

[daveSanborn]

You could drill a hole on the inside but I doubt you will have enough room to try and weld a nut in there

Why would nuts need to be welded inside the framerail?  With holes drilled on the inside of the framerail to allow access, simply install a nut and washer onto the bolt and tighten.  The internal nut doesn't "have to be" welded in place.  It's technically not welded in place on factory installs... it's retained within the aforementioned "cage".

[Ponyman66]

Dave's correct (like you needed me telling you that, right Dave?!), if you drill access holes for the nuts. Cosmetically though, you'll need to leave the holes open (or install removable plugs).

I said I'd get some pics up of my recent repair. Sorry, I fell asleep in the recliner after coming from working on the car last night! Here's a pic of the frame rail (inside), after cutting open, welding in the nuts, re-welding the removed sections and cleaning them up:



Here's what they look like from the outside frame rail:



From a cosmetic stand point, I prefer this method as it doesn't look like anything was done. I think it's a forgone conclusion, there's many ways to do the repair, you just need to figure out which you prefer.

[napaguy]

Why would I be kidding?  The steel on all four sides was rusted through in places and it was easier to replace the front frame rail than to patch it.

I understand the repair you did on your car but your reply was that he think abut replacing the rail on HIS CAR...there is nothing I see that would warrant that type of repair...unless im missing something?

[Midlife]

Look at the pics on Reply#7.  The frame rail has some serious rust going on, on fairly thick metal.  His bolt broke off on the interior, which he cannot see right now without cutting into it.  The frame rail is one of the main structural pieces, and the bottom side is probably rusted worse of all of the sides.  No pictures of the underside.

Would you like to have your Mustang held together by a frame rail that is known to be rusted, and then have a front-end accident?  I know that I wouldn't.

I merely suggested that replacing the entire frame rail is an option worth considering.  Patching scaly, rusty metal by welding to it is no fun. 

[mustangstofear]

Yes he could simply add a nut and a washer, but he will sill have a rotten twisted bracket to contend with. Like I said in the beginning make 3 cuts bend it down and weld the nuts on the back side like Ford should have done in the first place. Rich.