I'm not condoning GM doing this but JB Weld does work! I broke a tooth on the idler gear in my modified FJ40 Transfer case. The tooth went through bottom of case. It was my daily driver at the time so I fished the tooth out and JB Welded the hole closed. Drove 2 weeks that way until I could pull case and replace gear. I had a coworker weld the hole shut. Been using case for 3 years now. Case too thin to weld? I seen this guy weld coke cans together end to end with a tig welder with no holes.