I can’t remove my seatbelt

Question:

I have a 1976 Corvette Stingray and I'm having problems getting the seatbelt out of the car on the passenger side. I have been able to get a socket on the head of the bolt, but I can’t get it to move. The bolt is through the fender well and the problem is that I can’t heat it up with a torch for fear of damaging the fiberglass. I tried an aerosol can to freeze it but that didn’t work. I’ve also tried several different kinds of penetrating oils but I had no luck with that either. I need to get the seatbelt out because the retractor under the seat is broken.

Answer:

In all likelihood, the bolt is rusted to its nut. If you could lower the temperature of the bolt sufficiently it would likely help because the metal would shrink. But in order to lower it enough you’d have to immerse it in dry ice for a while. Spraying it with an aerosol will not do the job. Soaking the area where the bolt and nut come together with penetrating oil might help but it’s difficult to even access this area. Spraying the head of the bolt won’t help and if the bolt and nut are very rusty penetrating oil probably won’t get between them.

If the bolt and nut are very rusty and you apply sufficient force to the bolt you probably will break it. That’ll get the seat belt out but it will be a monumental pain to reinstall it. You’ll have to drill the broken bolt out and then tap the hole to fix the threads. The bolt is made from very hard steel and it will be a chore-and-ahalf to drill it out and even hard to drill exactly in the middle to avoid drilling into and ruining the nut.

The best solution in these circumstances can usually be found at the business end of a torch. The nut is welded to a plate and if you put the car up on a lift you can access it.

The most effective way to free the bolt is to heat up the nut with a torch until it is glowing hot. A small oxyacetylene torch is the most practical choice for this. If you control the flame well you should be able to get the nut hot without lighting the fiberglass on fire. Have a socket or wrench on the bolt and ready to go as you’re heating it.