2006 Tundra 4.7. Coolant dripping from dust protector on bell housing. Pulled trany and saw 2 small rusted out holes just above flywheel, they were not the freeze plugs. It appears to be the thin walls of the water jacket, did Toyota make the walls of the engine that thin that they would rust out? Do not want to weld but can we use JB weld to seal up the small holes?