Rocker Panel Captive Nut Repair

[Robert S.]

The drivers side rocker panel on my 74' (and I assume most if not all C3's) is held on by 3 bolts with nuts accessible from the back side and the rest are bolts that thread into some type of captive nut. I think these are 10-24 thread. I was able to easily remove the three bolts attached with nuts. However on the first bolt that went into a captive nut, the bolt broke as I attempted to remove it. I stopped at that point as I was able to get the access panel below the charcoal cannister off by flexing the rocker panel a little. So, at this point, I have no need to remove the remaining rocker panel bolts.
I assume this has happened to others and am looking for some advice as to how to best proceed to repair the broken rocker panel bolt. Should I try to remove the rest of the bolts that go into captive nuts and risk breaking them off but have clear access to all of the captive nuts? If I do this are the captive nuts easy to replace? Or should I try to drill out the remains of the broken bolt through the bolt hole in the rocker panel and try to retap or install a longer bolt and put a nut on the back side? I am leaning towards the first solution as I assume drilling out the bolt remains through a blind hole would be tricky to stay on center. However I also hate the idea of purposely doing more damage by breaking bolts off. What is the best advice? Also can someone describe to me what these captive nuts look like and are they installed, at the factory, from the rocker panel side?

[Christopher K.]

Re: Rocker Panel Captive Nut Repair

Robert,

First of all, I would soak them with PB Blaster. It sprays on like wd-40 but works better than anything else I've used. I would wait a day and then hit them again. Then I would use a drill to extract the screws. This should reduce the possibility of breaking off those nuts. If you can't get the screw out this way, or its strips, I would try drilling a hole and then using a screw extractor bit.
Be very careful with the forward screw by the charcoal filter. My PO cracked the fender in this area trying to get it out.
Most corvette suppliers also stock a rocker repair kit, if you do end up drilling those screws out.

Good luck,
Chris