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rear cradle reinforcement bolts broken

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#1
ptk

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As I was trying to remove the rear cradle reinforcment (support structure of 5 tubular bars that stiffen the bottom of the rear cradle), I twisted the bolt heads off of 3 of the 6 bolts.  These have weld nuts in a welded bracket on the cradle, and I am wondering the best way to remove the rest of the bolt.

I think many people will tell me to drill out the bolt, but I have never had the skill or luck to drill out a bolt through at least a few times trying.  Either I am using the wrong types of bits or wrong drill or just wrong approach, but I will typically waste a couple of hours and either give up because the hole is only a couple of millimeters deep or break a bit inside the hole just to make it more difficult.  

I would like to grind the weld nut off, but it's not great access to do that.

The last idea I had is to cut the bracket out around the weld nut and then weld in a replacement bottom plate for the bracket and use a loose nut instead.

Anyone have experience with these particular joints or other similar?

Thanks again - this forum is awesome



#2
Ron Alan

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Clearly you had a rusty subframe? Pick up a new subframe and replace yours! If the bolts wouldn't come out don't waste your time trying to get them out!! If you were in CA I'd give you one...I have a pile! If you havent had other nuts and bolts off be prepared to potentially break a few more...spray everything with WD40 or similar before removing anything else


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#3
Dave D.

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To get the welded nuts off, I have had good results putting a short 19mm socket on a breaker bar(or a box wrench with extension if bad  access) and twisting the spot welds to the breaking point(they really aren't welded on that strongly). Then either nut and bolt them in or tack a new nut in place with a little MIG spotweld. I have found sometimes P.Os have used wrong bolts to hold the brace in(using coarse thread instead of 1.25 fine, and they just force them in with an impact.


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#4
ptk

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Brilliant!  Breaking them off worked great.  Not too difficult and they broke cleanly, with a nice surface for a new nut.  Thanks again for the tip






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