Rusted nerfed bar mount holes fix?

The mounting holes on my 07 are pretty rusted. Can't get a M8 bolt to catch. What's left of the threads are kind of breaking away. Anyone had success with this? What did you do?

Maybe drill it out and re-tap with a m9 or m10?

 

hard to tell from the pic, but can you get to the top side? If so, just drill em out, get a longer bolt and put a nut on top of the rusted stripped out (and drilled out) nut.

 

Can't access the top side. Checking what matching bolts and tap I have.

 

If those welded nuts are spot welded just like they are on the frame (which they are) the internal nuts will break the welds upon attempting to tap and rethread them which will cause them to shift around and slide around as you drive. I would leave it alone and plug them up unless you want to go the extra mile and remove them from the top which would require cutting into the cab top metal which would ideally require you seal it back up once they have all been removed. You are better off getting steps which mount to the frame anyways.

 

This is exactly what I did for my uncle's truck. The back two bolt holes were completely rusted out, so we drilled out to the next size up and threaded it.
Took some time, but in the end it worked perfectly fine.

 

What would you use to plug these? I took my steps off and may put some others back on in the future but I want to preserve the holes.

 

So far so good. Drilled out with 5/16 and tapped with 3/8-16nc.

 

Plastic bolts are installed from the factory. You should be able to order them.

 

Thanks