I am trying to install a trailer hitch on my 2011 Toyota Camry. I have to lower the exhaust. All bolts (14mm or 9/16") are removed except the one with a special hex nut (not sure is a hex or not but looks like).

I call it a special hex nut because all tool heads I have cannot fit that nut. And from the picture you can see it is not a regular hex nut because it seems it doesn't have equal sides.

My question is where I can find a proper tool to hold that nut and then I can screw it out?

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  • Why won't a normal open ended spanner fit?
    – HandyHowie
    Sep 22 '15 at 19:13
  • I also tried the open ended spanner. there is no enough space in both directions. Sep 22 '15 at 19:40
  • Do you think it is meant to be welded to the panel it is on?
    – HandyHowie
    Sep 22 '15 at 19:49
  • The bolt side looks like a normal hex ... is that correct? Sep 22 '15 at 20:21
  • @HandyHowie, I think you are right. It looks like it was welded to the panel but somehow I broke the weld. that is why I am trying to find a way to hold that nut. Sep 23 '15 at 0:59

The nut you are referring to is meant to be welded in place. The bolt then threads into and out of this nut without it moving. What you have run in to is that the bolt is so rusted in the nut, that it broke the welds and now the nut is spinning.

The bad news is that they don't make special tools for welded nuts.

A set of locking pliers sometimes called vice grips should hold the nut in place while you unscrew the bolt. If the bolt is that rusted it may require some heat (blow torch) to get it loose. Worst case scenario is to cut or drill the head of the bolt off to release the bracket and then replace it with just a regular bolt and nut.

  • I'd add that exhaust hardware is notorious for this. It's already damaged, so I would just go ahead and cut it off. Replace it with the correct part from the dealer, though, not just any old metric bolt and nut from the hardware store. Sep 22 '15 at 22:23
  • @dodgethesteamroller replacing this with dealer hardware is going to prove difficult as the dealer does not sell welded nuts. You can buy the bolt from the dealer if you want but it would be up to you to get a new nut some place else.
    – vini_i
    Sep 22 '15 at 23:04
  • I am surprised to hear that, as Toyota generally has available every possible part for my Lexus. Nevertheless, I was concerned mostly with the OP using fasteners of the correct grade (rather than the cheap stuff sold loose at neighborhood hardware stors). Any auto parts store should be able to supply metric nuts and bolts in standard sizes that are suitable for exhaust flanges. Sep 22 '15 at 23:15

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