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Is there a way to weld this captive nut? Cut frame rail and have limited access


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Yesterday I cut into the frame rail to address a broken captive nut on the front transverse bushing bolt on my 03 Outback. What a mess.

 

1.  Welded the nut 3 times and the welds broke very easily. I have no access to clean the metal, is that the problem?

 

* Would a better welder work?  I'm using a cheap wire-feed mig with no gas.


*  Are other welders able to get into small places?

 

I may try to squeeze a long grinding stone in there with a drill and clean up the metal and try one more time.

 

One KEY that I've never seen mentioned - the captive nut is ***ROUND***.  Picture attached. Can't get anything on it to tighten it by hand.  The bolt is also too long to fit another nut on top of it. Cutting it out is going to be a debacle, there's no gap to get in between and every orientation of my angle grinder and sawzall puts it at an angle, not flush.


If I ever see this on a vehicle that's not worth much I'd just weld the transverse bushing directly to the vehicle.

post-3989-0-60565300-1400931074_thumb.jpg

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You need to use a welder with gas or a  good stick welder

 

If all else fails get a hole saw and cut a hole above the bolt. then oil the bolt and slip a spring washer and a  nut on the bolt. then tighten it up using what ever tools you can to get it nice and tight.

 

TOONGA

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Can you turn up the amp setting on the machine? If yes, crank it up and it might burn through the rust/paint/crud in there.

 

If not, weld some lines on the side of the nut, see if you can turn it into a square so you can put a wrench or vice grip on it. Then try to loosen it while its still hot.

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Can you turn up the amp setting on the machine? If yes, crank it up and it might burn through the rust/paint/crud in there.

 

If not, weld some lines on the side of the nut, see if you can turn it into a square so you can put a wrench or vice grip on it. Then try to loosen it while its still hot.

 

i had it cranked almost all the way. i'll bump it all the way and hit it with a grinding stone on my drill and give it one more shot.

the access is so limited making a line is unlikely.  i thought about just welding a wrench or metal bar to the nut so it held it...same idea.

 

If all else fails get a hole saw and cut a hole above the bolt. A

 

i tried that a couple months ago. on a 2003 Outback Sedan, that is not the way to do this job, too convoluted due to the many layers of metal, deep access, many turns/indirect line of sight, etc.

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I have a cutting torch - how hard is it to "burn" the head of the bolt off?

 

Keep in mind I haven't dialed it in and have never cut with a torch before, let alone this one.

 

The undercoating was catching on fire lightly while I was welding - so that's a little intimidating.

 

I could then at least get a nut on there, but then it'll just be a debacle if someone tried to loosen that bolt in the future- alignment, etc.

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If you've never used a cutting torch, a confined space under a car is not the place to start. Acetelene is also very dangerous to use if you don't know what you're doing. It would certainly make short work of the bolt, along with the bushing housing, and the bushing.

I'd be more inclined to use the sawzall to cut the head off.

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If you've never used a cutting torch, a confined space under a car is not the place to start. Acetelene is also very dangerous to use if you don't know what you're doing. It would certainly make short work of the bolt, along with the bushing housing, and the bushing.

I'd be more inclined to use the sawzall to cut the head off.

 

i'm using propane since it's more available in a rural area and the acetylene did scare me!  hopefully i can just get the dumb thing welded, but i may practice burning a bolt head off the car to see.  eventually i need to learn to use that torch.

 

the sawzall has no good angle to cut, pressed up against the car the blade isn't "flush" or parallel  it's at an angle to cut the bolt head, so it'll be a long messy battle to cut it off.  i'll have to remove the control arm, cut the  transverse link bracket off so there's just a small square left under the bolt to have any reasonable access at all.  which is fine...but then i'm still left with welding something in there!

Edited by grossgary
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Yeah those bolts aren't easy to cut anyway. Pretty sure they're 10.9 steel, (equivalent to Grade 8).

 

Cutting wheel on a die grinder would be my preferred method if air tools are an option. If not, a 4" angle grinder would work, just would take a while.

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i have a die grinder.  why is that quicker than angle grinder (i have both)?

it would certainly give me better access/articulation with the air die grinder, I never use that to cut off stuff, i need to change that.

 

where/what attachments do i get to use that to cut - is that obvious at a parts store?
 

those hard bolts take forever, they're nearly impossible to drill out.

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I'm only going off your description and picture,but I'd still try to weld it. MIG's work great for sheet metal, but you have to run the gas nozzle on your gun for it to work, which is just going to get in the way. I'd still use the flux core wire(your using flux core right?) If your running standard wire with no gas your weld wont hold for spoob. Are you running your electrode positive or negative? Keeping the electrode oriented correctly will help burn through crap in there. MIG=electrode pos. FC=electrode neg... Keep in mind on a flux core setup the gun doesn't have to be near the weld like a MIG setup. Situations like this I'll hold the wire and guide it after it comes out of the gun, which helps on really sharp turns and tight pockets. 

 

Keep a supersoaker(they don't make a mess like a fie extinguisher does) around for fires and have someone else there to spot them.

 

Josh

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If your running standard wire with no gas your weld wont hold for spoob.

 

i don't know anything about welders.  mine can't be fitted with gas...i would assume i have flux-core wire but i'm not even sure what that means.  i've welded sheet metal before, welded the frame of my Kubota tractor (not your average Lowes grass cutter), etc, and it holds fine so I expected it to work here?

Edited by grossgary
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i don't know anything about welders.  mine can't be fitted with gas...i would assume i have flux-core wire but i'm not even sure what that means.  i've welded sheet metal before, welded the frame of my Kubota tractor (not your average Lowes grass cutter), etc, and it holds fine so I expected it to work here?

 

The spool of wire will say flux core on it. It means the wire is actually hollow and filled with flux. You likely have paint,scale or rust thats keeping it from penning, sometimes just scratching the surface with a screw driver will give it enough bare metal to burn everything off. 

 

Check out the miller website if your looking for some good tutorials

 

Josh

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Gary, do you think you could get your die grinder on opposing sides of that nut to give a vice grip something to hold onto?

 

grinding yes. vice grips won't work though. as you open the handle it doesn't even come close to fitting - handles run into the frame rail area. very little room for anything. i can get a box ended wrench over it - that's about it, no more room for any handles opening, etc.

 

in the same way you're thinking though, i've considered cutting a notch in the side of the fastener to put a large chisel into and hold it in place.  the bolt/fastener are loose and wiggling in place, so they're not tight to the vehicle, just corroded.  i guess if i have room to cut a notch i can probably just cut it off.

 

 

Is there room to get a nut splitter up there? The power of the almighty wedge.

 

Google Image Link with many sizes and shapes

 

is the wedge comment a poke at my fondness for XT6's?  LOL

 

that would be awesome, not enough room to get a nut on top of the bolt as it's very close to the ceiling - i was going to thread a nut on and tighten it.  anything completely circular in form won't work unless it's very thin.

 

 

thanks guys:  current approach is:

 

1. grind and expose metal

2. turn up amps all the way on welder

3. cut notch/drill hole in captive nut to try and pin it in place

4. cut off the bolt

5. weld a nut to flat plate (or a wrench) and have that plate extend through the bottom cut i've already made as i weld it all back together.

 

are wrenches weldable - they have that "chrome" plate?

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Tscratching the surface with a screw driver will give it enough bare metal

 

i did try that but wasn't getting much, not much room, leverage to work with and gouge the metal but i think this is what's needed.

it kept cutting on and off like it wasn't properly grounding, probably a clear indicator it wasn't grounding.

Edited by grossgary
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IF you can get at the nut with a grinding stone & die grinder, you could weld a piece of 1/4-5/16" round or square stock to the nut to stop it from spinning. Two beads on two sides of the metal rod may do. Put the ground clamp on the metal rod to weld it to the nut. Tack it, wire brush the nut, crank up the amps, then burn it in good.

The heat may then break the rust bonding the threads & while its still hot back the bolt out. 

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Put the ground clamp on the metal rod to weld it to the nut. 

 

That's a GREAT idea, I don't have a great clamping point due to the small access, i'm clamping to the bolt head so it's going through that and into the captive nut, probably not a good connection.

 

 

 

Any chance you could tackle this from the other end? Meaning cut/grind off the head of the bolt. 

 

It'll be a pain.  my angle grinder and sawzall are always at an angle and can't cut flush, they're always hitting something, something is in the way, it'll be convoluted.  possible but probably a multi-step process.

 

 

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Can you drill from the bottom?

Start small and work up until you can pop the head off the bolt

 

those bolts are hard and brutal to drill through. but I could angle grind the head of the bolt 5 times straight on from the top to get it off too since i can't cut it flush due to clearance issues. same idea, and would be quicker. 

Edited by grossgary
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